I'm going to skip over the...
disappointing results of the suspect in favour of talking about the new mons we got, or at least the ones I think will be okay. If I didn't talk about your favourite new drop, it was probably intentional.
Regular Sandshrew sucks, but Alolan Sandshrew might see some sort of niche with snowpix and slush rush, although sun teams are probably just better. Its typing is okay, Ice STAB is pretty good in this meta, but part of the reason Piloswine's so good is because it has a second great STAB backing it up, and Snowshrew just doesn't. Might be cute to try.
While it appeared to have missed out on all the cool new toys Poliwrath got as a result of politoed existing, Poliwhirl will probably carve itself a niche as a secondary rain sweeper, or just BD sets in general. It is probably the second best rain abuser in the tier behind Lombre since it can break Roselia at +6, which is a feat Lombre can't match, but full rain is practically nonexistent and I'm not sure self-rain + BD is a good idea. Shame about those Poliwrath moves.
Be very, very grateful that this thing doesn't get NP. And that it shares checks with Haunter. I honestly wouldn't be surprised if this thing gets at least suspected, as it's broadly a second haunter, except with more speed and power with a worse STAB backing it up. It notably outspeeds Linoone, meaning that "switch your Linoone in and hope they clicked the move you're immune to" isn't a particularly great strategy since if it's weak enough Kadabra can pick it off anyways. CounterSash being a potential option reduces the number of safe switchins as well, since it can choose to stay in and kill your scarf Krokorok if it wants to. Lastly, Pursuit being gone makes Kadabra even scarier, for obvious reasons. Should Kadabra go, I could see Abra being somewhat viable, with 105 SpA and 90 Speed actually putting it barely behind Haunter itself in terms of speed and power, in addition to CounterSash sets working here too.
Seems niche but cute as a tspiker or spinner, even if Hattrem probably makes its life hell. Don't have much to add here.
While Galarian and regular Slowpoke are largely the same, even having identical stats, regular Slowpoke getting Teleport and Galarian Slowpoke not probably makes the regular one the definitive one. Regen + Teleport sounds extremely cool on paper, but I have a feeling its stats might let it down here. It's also not really a Machoke check since it's weak to Knock Off and hates losing eviolite, but it can switch into non-FO sets well with regenerator, even if it loses to Flame Orb. Mareanie existing sucks for it, but Teleport might be enough to make up for it. Maybe.
I'm going to lump these two together because I don't expect Magneton to stick around very long. Losing HP Fire/Grass is admittedly bad for Magneton, but it can still trap Resttalk/Shift/Gear Grind Klang as timid Specs TBolt 3HKOs the standard set, and because Magneton's faster it kills it before it can use rest a second time (Klang rolling Shift Gear messes this up, obviously, so it's not perfect, but forcing Klang to rest is pretty easy to take advantage of even if you don't get the trap off. Just something to note). If you want to forgo being able to trap Klang for other broken or potentially broken pokemon like Haunter or Kadabra, specs Analytic will generally wreck everything not named Palpitoad, which takes about 70 minimum (PhysDef, SpDef is probably an option but then you lose to other things you want it to check, such as Raboot or Piloswine) from Analytic Steel Beam if you can get a good read, even if it's slightly impractical due to Magneton losing HP. Magneton with good prediction feels like it'll have little to no counterplay, crappy volt absorb mons like electrike don't count and also die to flash cannon, and even if you can revenge it that doesn't matter if you can't switch it in safely. Magnemite keeps the trapping abilities, matching the feat of 3HKOing Klang while also outspeeding it with Modest Specs (see above for shift gear), but lacks the breaking-the-tier-in-half qualities that Magneton gets, making it more niche. I suppose you could try some sort of weird Iron Defense + Body Press set to trap both Klang and Ferro at the cost of only doing that and losing most of your general ability to hit stuff hard, but I'm not sure how successful that would be in the long run, especially on Magnemite.
Massive moveset and good bulk, but feels lacking in other areas. I'm sure some madman who enjoys playing full stall can find some use for it.
I don't think I really need to elaborate on why this needs to be banned. Teleport just makes it worse, since now it doesn't even invite Machoke in for free that often. I'm also not covering Happiny for again, what I assume to be obvious reasons.
Probably the best check to Machoke we got here, although I need to point out that Knock into CC kills after rocks, and two CCs kills in general against Guts Machoke. Not the biggest deal in the world thanks to Regen, but it does take some effort to be able to beat Flame Orb by itself. I'm not too versed in this mon, but Knock + Regen seems cool. Its biggest problem is going to be trying to not be passive enough to let half the tier in for free, but Knock Off ultimately helps. Like Slowpoke, it probably hates losing its item, but it's not as big a deal due to overall better stats.
Unfortunately, not getting Hurricane like Kingdra probably kills its viability as a rain sweeper for as long as Roselia is a viable choice in the tier. Flip Turn would be cool with specs, but again, Roselia is in the tier, as while as other things like Mareanie, Brionne and even Palpitoad. Maybe Sniper sets could be worth it, but I have serious doubts it'll ever be good.
It gets Spin, Teleport, Recover, and no bulk to abuse any of that. Offensive spin with Analytic might be cool, since it can pressure Roselia and Mareanie with psychic moves, even if it doesn't get STAB on them. It might not hit hard enough for that, though, but I see at least some potential here.
Please refer to my first sentence on Chansey. It was already broken last gen, and now it gets access to Heavy-Duty Boots to mitigate its biggest weakness, as while as Dual Wingbeat to circumvent what we thought would be the opportunity cost of using boots on Scyther. It's almost certainly way too strong for the tier.
Let me just get this out of the way: Unless you're running some ungodly physically defensive Marill set, this thing loses to every Machoke set bar maybe resttalk. BD + AJet could be cute, but I get the feeling that its stats might let it down in the long run. Sap Sipper sets are effectively dead as well, considering that Rose, Dartrix, and Gloom all have secondary STABs, but I guess it comes in on Tangela if your team's really weak to it.
Z-Conversion is gone, but I can't help but feel that this might be too bulky for the tier to handle. It'll be a really good general check to anything not named Machoke if it does stay, given its huge bulk and self-sufficiency. I wasn't around when this got banned last gen, so I don't have much to add here.
Okay, it's probably bad, but it's a normal type that bypasses Corsola and can hit Klang for SE damage. I'm expecting nothing from it but I could see either Specs or Band at least being worth trying, since its coverage is genuinely crazy.
Cute spikes lead. Hattrem kind of messes with it, unfortunately, and Machoke and Haunter's influence (plus likely several of the new things in this post) have probably made the tier too bulky for a semi-suicide lead to thrive. Definitely good at what it does, it just depends on if what it does is good in the meta at any given time.
The first Pokemon we get that actually resists both of Specs Haunter's STABs, although Dazzling Gleam drops it. I could see it having several niches, mostly the same from last gen with rocks and scarf moxie, but its stats might let it down despite the amazing typing. If you're running scarf Krokorok to revenge Kadabra, you probably want Beat Up on it over Pursuit this gen to bypass sash.
It's a worse Tangela with Spore and a fighting resistance, as while as a poison neutrality that won't save it against Haunter. ultimately probably not worth it unless Spore is that good, and the fighting resistance doesn't save it from dying to Machoke (see a trend here?), but there could be something here.
It's sort of hurt by Machoke's existence, since it both has to compete with bulky versions for a teamslot and everything's out for Machoke's head, but Regenerator + U-Turn will probably make for a niche but usable offensive pivot. It also picked up CC this gen,which means switching in a Ghost on it isn't as big a deal. I see it being pretty alright, but it's definitely going to be uncommon when Machoke is right there.
Boots lets it use its kind of neat typing defensively, and it's got wisp, u-turn, and recovery. Having to pick between boots and eviolite on a defensive pokemon is miserable and is likely to ultimately hold it back, and despite the fighting resist, it doesn't check Machoke regardless of which item you pick. It'll probably have a niche, but it might be way too weak to Knock Off to really use, considering our hazard removal still isn't that great.
Boots! It actually gets a good STAB to use with them, too since it also picked up Dual Wingbeat, although the power drop from Acrobatics is noticeable (~35 base power difference). I don't see offensive sets really taking off given how bulky the meta is, especially since we got like seven new regenerator mons in this DLC, but I could see something like taunt/roost/defog/wingbeat with boots being nice, as priority defog is a godsend for certain teams. It also revenges Kadabra as long as it hasn't taken a hit, even through countersash, courtesy of dual wingbeat. Definitely improved from gen 7, but it might end up being metagame-dependant.
Maybe there's something here? It picked up Flip Turn, which gives it a STAB Adaptability-boosted U-Turn, but its stats are genuinely awful. Adaptability Specs with Hydro/Sludge Wave/Flipturn/Tbolt could be neat, or maybe dropping one of those moves for Toxic Spikes and going bulky while still retaining a reasonable amount of firepower thanks to adaptability.
It's a worse Hippopotas defensively but hits harder with Ground Scald. Theoretically it can do everything Hippopotas can while hitting harder, but the added weaknesses Ghost typing brings with no useful resistances probably dooms it.
Maybe I'll do a part 2 of this where I talk about some cool new moves older Pokemon got, but I'm lazy, so don't expect it.