This is getting a little ridiculous. Keeping a few potentially (keyword: potentially) overpowered things in check is not a good reason to keep Aegislash.
For one thing, we don't keep broken shit to check broken shit. Furthermore, this thread is the first time I have heard anyone say, in any capacity, that Mega Garde/Cham/Hera are overpowered. "If we ban Aegislash we might have to ban these three;" really? You think that? Aegislash, a pokemon that stall does not use, is the one, singular reason that these pokemon, which already have respectable usage and viability, are completely dominating and 6-0'ing every stall team they run into?
But most importantly: Stall is already really quite good and hard to break. It will only improve if future suspects, namely Mega Maw, X-zard (okay stall uses this but it's still a huge pain for them to vs.,) Thundurus, and Landorus, get banned: not to mention Aegislash itself. Is it so bad that stallbreakers will increase in viability? Especially stallbreakers that both have an opportunity cost for running them (Garde and Cham are not so great against HO, Mega Hera is bulky but a lot of things can RK,) and for which stall is not completely helpless; Slowbro/Mew/Cresselia for Cham (all of those benefit from Aegislash going, btw,) Mega Scizor for Garde, uh idk for Heracross (Weezing?) but Gliscor can probably do something. Not to mention Garde and Cham both have abysmal defenses so even uninvested attacks from a number of walls are going to 2HKO.
There are people acting like these three, as well as stuff like Close Combat Pinsir, are going to become huge problems without Aegislash. To people who have actually played on the suspect ladder: is this really the case?
I've played about a 100 battles on the suspect ladder, so I feel I have a pretty informed opinion on what people are running. For the record, I ran a stall team (Chans/Tini/Zap/Amoonguss/Mola/Heracross) and bird spam (Pinsir/Tflame/Latios/Landy-T/Keldeo/Thundy).
Mega Heracross
This thing, my god. The first and obvious thing is that offensive teams don't struggle with Heracross most of the time. The extra birdspam on the ladder is indicative of this. But
all it really needs is a single turn to demolish anything. The only switch-in that offensive teams have in an Aegislash-less meta is Landorus-T. Lando-T has that main problem of being worn down by hazards alongside a lack of reliable recovery. Second, Lando-T has some serious opportunity costs to "walling" M-Heracross: if you choose to use a full defensive spread (only 4HKOd), you can only 3HKO M-Heracross at best
and you don't outspeed, which means you can actually lose if you a) miss, b) switch-in, c) set up stealth rocks instead of attacking. Oh, the worst is that Heracross has the bulk to switch in on Lando-T
instead and then threaten with a 2/3HKO or just OHKO something else on your team. Gligar and Weezing are garbage and I wouldn't suggest them for a serious team--Gliscor solidly walls him, actually. I think Talonflame + M-Heracross + Landorus-T could be an interesting offensive core that like regular birdspam, wears down its counters over time. Anywho, when it comes to moves we all know that M-Heracross was forced to run EQ. Well, now, it can run Close Combat / Bullet Seed / Rock Blast / Pin Missile and my god, ladies and gentlemen, that is the stuff that makes you shit your pants. Skarm gets 2HKO'd. Hippo gets wrecked. I think only twice that I ran into M-Heracross did I win. The only foreseeable way stall could beat this thing is Scarf Gothitelle, which loses to Sub. Also everything loses to SD, which no longer needs Bisharp's Pursuit support to be successful. It's honestly strange how a small change in coverage can be such a big deal. And yeah, a lot of things can RK M-Heracross but he has the bulk to survive Specs Keldeo's Scald if you EV it right and Pinsir/Talonflame are easy to account for imo. Granted, Latios, and anything remotely fast can still destroy you, but M-Heracross just screws up stall so much
while not being worthless against Offense like Gothitelle, that the opportunity cost is minimal.
Mega Medicham
Mega Medicham is obviously more prevalent on the suspect ladder, but it now has more varied options in what it can run. I've seen some people stick to the HJK / Psycho Cut / Fire Punch formula even though there aren't many benefits to it. Skarmory still gets screwed over by HJK, so yeah, not sure why people are running it. I've seen a lot of people run HJK / PC / Ice Punch instead, alongside Drain Punch which screws over stalls bulkier walls. Oh, and to note to that: yeah, Mega Medicham completely screws over stall. Slowbro gets 2HKOd by Thunder Punch after rocks, which it can now afford to run; Mew gets screwd over by Substitute sets, which I've seen a lot of as well. Cresselia is...well Cresselia. Stalltini, which I ran, deals with it efficiently, but honestly, Stalltini is so underwhelming when it lacks reliable recovery and it, too, gets screwed by Substitute sets since it gets worn down really easily with HJK + SR + defense/speed drops from V-create. Otherwise, if you're opponent is dumb, you can burn it on the switch. M-Medicham might be weak but there aren't many dedicated walls that can 2HKO it when its gaining back health with Drain Punch. Sableye is a good counter / stallbreaker too here. One thing that I think will happen is that a lot more niche / lure sets are going to be developed. For example, Rock Tomb / Force Palm can work for a lot of its common offensive switch-ins (there aren't many) and then smash them with a super effective attack. A SubPunch set a la Mawile could work just because it forces so many switches. Some people might even run Bullet Punch in the last slot just to have that nice extra priority. I'm not saying those three sets are amazing, but the reason why they don't exist is because Aegislash exists and without the latter, you might start seeing the former. All of this being said, I haven't lost to anyone using Mega Medicham, I don't think, so
its capabilities as a wallbreaker might be overrated.
Mega Gardevoir
Gardy is no less ridiculous towards stall than it was before, but with Aegislash out of the picture, it can be really hard to stop solely because of the coverage it can now afford to run. Specially defensive Heatran is still a solid counter...unless it has, you know, HP Ground or Focus Blast, which I have seen (and the reason I ditched Heatran). Stalltini deals with sets lacking Shadow Ball. Mega-Scizor is an exception revenge-killer: it can OHKO with BP, 2HKO with BP if burned, 2HKOd by HP Fire (which is pretty impressive imo). However, like with previous mons mentioned, Gardevoir can now run SubWisp, SubCM, and some really random shit like SubDestinyBond just to mess with Scizor (haven't tested that one out, don't get mad at me if it sucks). And of course, it can run Focus Blast > Shadow Ball, which hits much more things, including the aforemnetioned Heatran for the 2HKO. Sub + 3 Attacks is definitely more effective in this ladder. It breaks stall even better than Mega Medicham and Mega Heracross by far and can't be statused or walled by much. I can definitely see Stall running M-Scizor a lot more just to deal with Gardevoir -- this isn't a bad thing though, since M-Scizor is a solid defensive Pokemon that's been strangely neglected.
If you lack M-Scizor and your opponent is competent, you're stall team will lose to M-Gardevoir.
BirdSpam
Ah, Birdspam HO. I actually want to address one thing first: the fact that Aegislash is no longer in the tier means that you can Staraptor, whoses STABs + Close Combat are not easily resisted. He's slightly harder to RK, doesn't require a mega slot, and has a stronger STAB combo with no Aegi to ruin it. Hawlucha, another Pokemon locked away in BL, gets a chance to shine with a menagerie of sets, including SD, SubSD, SubLiechi, etc, all of which do really well against HO because it's so hard to RK this thing after the Unburden boost. Nothing Scarfed that I can think of outspeeds it. Excadrill in the sand doesn't outspeed it. Kabutops in the rain doesn't outspeed it. It's only revenge-killable by our bravest bird. Hawlucha still has problems, like being unable to break things before a boost, having to rely on Unburden (although its speed stat is amazing, don't get me wrong), and still being walled by Zapdos. Finally, Pinsir gets Close Combat over EQ, which means it can OHKO T-Tar with ease, 2HKO Skarmory, and just in general have its STABs walled by fewer things. Stall can no longer rely on Skarm to wall it -- I actually switched to Zapdos to deal with it -- it's one good thing though that M-Pinsir still has checks and counters of sorts, it's just that that pool has decreased somewhat.
One Pokemon that I haven't addressed directly (but you're seeing the pattern) is Talonflame.
All of these threats are revenge-killed by Talonflame.
Does it even need to be said that the metagame will centralize towards Talonflame? Is this inherently a bad thing? I'm not sure. For one thing, it means that the power of all these threats (except Birdspam) is for the most part overrated. Most teams build with a Talonflame check in mind anyway and there are enough to go around.
I'm not certain how I'll vote. But this is what I've observed in the metagame.
And yes, stall is still viable.