We're losing the possibility of any double core ever existing
You can't run or vote on a suspect thread for what might happen in the future. Suspects are for what's happening in the metagame
now, not whatever theorymons may or may not exist in the future. If future possibilities can determine whether bans go through or not, then all bans can be rejected on the ground of "this might hurt something that could exist in the future" or "there might be something in the future that checks/counters this well enough to make a ban unnecessary".
Plus it's not like bans are forever. See Huge Power at the start of this gen, even though it was rebanned.
Also, the double species clause thing mentioned, which, while not my preferred option since it's weird compared to all others, it's better than nothing, IMO.
as for cores affected, theres no main ones...but that doesn't actually matter. there ARE cores that are going to be affected...offensive and defensive. i mean, the double groudon core i posted would be dead. double giratina, double chansey, double mewtwos (im guessing x and y will count as the same entity since they kind of ARE...and theres no reason to keep them apart. as the "they serve different roles" could easily be thrown to something like double groudon, or double ray) regardless they both cant use 2 of either, which some people DO use that. species clause would solve the problem of spamming kyogre and groudon....but why not just remove kyogre and groudon like we are about to do? as they are the only relivant two whom are unhealthaly spammable (and dual imposter somewhat, but seriously...do we really need a widespread clause specificly for nerfing it?)
It wouldn't be the first time things would be hurt by a ban. Ability clause killed a triple Regen-core I was working on a team that made most forms of stall just cry because their damage was too low to do anything to it. -Ate clause invalidates the Trick Room team I posted a replay of back over in the "creative BH sets" thread, not to mention nuked the Refrige Kyu-B/Kyu-W core. Would you want those clauses undone just to get those cores back?
That aside, the cores aren't dead, you just have to find different Pokemon, which is what you have to do in every other meta that's not Anything Goes, Classic Hackmons, or Custom Games, all of which are "no rules" metas. (And well, also No Species Clause OU if that's a thing. But if it is, it's clearly dead and unpopular.) I mean, take Arcanine, for example. In UU, if there was no species clause, I could easily run two or three different sets with different roles. Or take Mew for example. You could build a team of six of them and still have a dozen or so viable sets left over. But you can't, so you have to get a little more clever and determine which Pokemon would fill those roles the most effectively rather than just throwing the same mon with a different set there.
Also, my stance on this is about the current metagame, since, while the Hoenn trio, or at least some of them, are likely about to get the boot, that's not a 100% probability. The suspect was posted before that, so I have to vote and argue as if they aren't banned because, well... they're not right now. But, I doubt my position would change because if the whole big five were removed, they'd probably just get replaced with Mega-Diancie spam or Mega-Latios spam or whatever comes along as the next super-versatile offensive and defensive threat. (But if that didn't happen and people stopped spamming the same mon, then, well, my position probably would change.)
lets twist that question you said around: what does (barring dual imposter, kyogrespam, and groudonspam) species clause do to help the metagame? and dont say "it diversitizes the meta" as it clearly does not as i pointed out.
Well, to be blunt, it does. Let's say you're building a team and need a Mold Breaker sweeper. You look through your options and decide that Mega-Gengar is the best fit for your team at this point (because let's bring up a different example that's not at risk and not a problem mon). You decide then that you need something to harass and heckle your opponents team. You decide that a disruptive Normalize + Entrainment Ghost would be ideal. Without species clause, you'd probably just do a second Mega-Gengar. Channeling your inner Kit Kasai, you decide you want an Illusion user. There's a good chance you'll probably just go with Gengar
again. So, now you have three Gengars on your team. Sure, they have different roles, but that's not very diverse, now is it?
Without species clause, you might get to the first Gengar and be okay, but then you run into the second set and you have to stop and think. "Do I value Gengar more as a Mold Breaker or for Normalize + Entrainment disruption". And whichever role you put it in, then you have to think which Pokemon might fit the other role rather well. In this case, you might decide that Giratina-O, a Pokemon that's normally overlooked, might make for a good Mold Breaker sweeper since it has a number of qualities Gengar does, but you want Gengar's speed for the disruption more since, while Giratina is bulky, it's not very fast. Then when you get to the third, Illusion member, you have to stop and think again if you value Gengar where it is now or if you'd rather it be an Illusion user. You might channel your inner Kit Kasai even more and pick Chandelure instead, and then change your -ate to Kyurem or Rayquaza for even more sneaky Illusion fun, rather than just throw another Gengar in there and call it a day.
In the end, you have three Pokemon all with different roles, but in one case you're just spamming the same mon while in the other you have three different mons and need to account for their unique strengths and weaknesses rather than just plop down one "Gengar-counter-counter" and call it a day. Your team is more diverse because you have different Pokemon (although the number of Ghosts on this theoretical team is alarming in my opinion, but just bear with me since I'm thinking this up as I type) and the decision making in building your team is far more involved and interesting.
And you cannot tell me that the results of species clause there is a bad thing because you have to make those types of species-related decisions in every single metagame, Smogon or VGC, besides this one, CH, AG, CG, and if it even exists, that NSCOU thing. If it was a bad thing, then species clause would not be so prevalent in 90+% of all competitive Pokemon metagames. And while BH is a bit different due to its lax limits, it still has some metagames very similar where you'd be making the types of decisions I just brought up (AAA and Stabmons are probably the closest.)
Oh, and since we're twisting questions around, lemme ask you this. Pretend species clause was in BH and you thought it should go. What arguments would you make to remove it? Or another theoretical along those lines, what arguments would you use to bring it up to remove it from another metagame, official or unofficial. I mean, your points are valid since, as I mentioned above, I could run a dozen Mews that all have different roles. But surely those have been brought up before, right?
...of course, I realize this is all probably pointless and I'm most likely wasting my time because I doubt Yes will get 10+ more votes without No getting any before the end and I imagine a lot of No votes are there to help get the Hoenn trio banned in the next suspect rather than having species clause used against such a ban. But, I guess I just like making long-winded replies about my opinion. That or I feel more strongly on this than I'm willing to admit even to myself.
a few things, fur coat chanseys niche, is being able to take on ates...and being the BEST user to do so, since theres no ate user i know off that likes to use knock off over coverage,it also lets your ate use thousand arrows/earth power to get past pokemon like registeel and soundproof slowbro. this niche can not even be done as easily as chansey could let it, as even bliss has troubles managing rays power. its not meant to be fighting groudon, as v-create roasts it either way.
I'm not arguing Fur Coat Chansey's viability any further in this thread since it's off topic and I don't want either of us to get modsmacked. I'll also resist the urge to drop more of my opinion on the matter in this post because that's not fair for me to do so. But if you or anyone else wants to keep talking about that, I'll be happy to explain my position in more detail and respond to this in the regular BH topic.