Going to add to bludz's post here by explaining why some things that were discussed didn't move :
Garchomp : The main reason this isn't S rank is that, unlike any S rank at the moment, it doesn't have one clear set which puts it in that rank, while each ste is very good they all have exploitable flaws. Phys Def is probably the most flawed despite being the most popular, it's pretty easy to switch into and gets severely worn down by Spikes and stuff. Offensive sets have a hard time switching into things, which means you often have to either stack weaknesses or heavily rely on priority to deal with stuff Phy Def Chomp is used for, it also gets very easily forced out due to Chomp's speed being pretty low by ORAS standard. It's got very common universal checks like Latios and Weavile. Overall it's a very meta-defining Pokemon, arguably the best in A+, but just falls short of S rank due to its inability to combine all its potential qualities into one set.
Togekiss : We were kinda split on this, but ultimately decided to keep it in B+ due to how much it struggles against not just offense, but balance teams that employ faster Pokemon specifically in order to deal with stuff like Togekiss, which are gaining popularity since they're more effective than the kind of super slow balance teams Togekiss destroys. The majority of teams that aren't just full stall have something to force Togekiss out once it sets up. Has a hard time doing much of anything when its offensive checks are still active, which ultimately relegates it to lategame cleaning more often than not. Overall, it's too inconsistent to really fit in A-.
Celebi : This thing has kinda been teetering on the edge of dropping for a while now due to being vulnerable to really popular stuff like Weavile and Torn-T, as well as the fatc that it needs to be kept really healthy at all times in order to handle what it's supposed to, however it's still a really good answer to various Water-types, Electric-types, and Fighting-types all of which are very popular, it has a ton of versatility with a giant list of utility moves (particularly TWave which is actually really good on it), and it has great synergy with really good Pokemon. It's not really on the same level as a lot of A- mons (particularly Serperior which is pretty noticeably better due to being far more offensively threatening and easy to use), but in the end, we decided we'd rather move stuff up from A- to A as opposed to drop A- ranks (as you can clearly see from our current slate)
Also, I'm going to to add a few secondary discussion points we recently brought up but didn't discuss to great length or make an official decision on. These aren't important as the ones bludz mentioned, but they're still things that might happen in the near future.
Mega Slowbro to A- : We refrained from moving this down for the time being but this will probably happen, it's just not as good as its regular forme since it's nowhere near as splashable or self-dependant. It can steamroll teams in theory, but in practice it ends up getting worn down by stuff like Leech Seed and Spikes and burns, and due to the lack of both lefotvers and regen it pretty much has one shot to sweep, if it's forced out after taking damage it just can't come back in. All that being said, offense is becoming more popular at the moment, and Mega Slowbro is very strong against that particular playstyle.
Rotom-W to A : It's gotten a bit better recently. The popularity of Torn-T, Talonflame and Sand are good news for it, as is the increasingly spikes-dominated metagame : it's one of the only Water-types with a Spikes immunity, making it a pain for those types of teams. Still, the flaws that made it drop in the first place are still there, it gets worn down extremely easily, has a hard time consistantly handling one Pokemon throughout the battle let alone multiple ones, and Pain Split and Rest are both pretty terrible recovery moves tbh.
Heatran to A : I realise how controversial this is, and fyi this probably isn't happening, at least not right now. But we all pretty much agreed that Heatran has gotten worse recently, it has a lot of flaws like lack of recovery, easy to wear down esp if not running protect, doesn't actually beat Fairies, non baloon sets hate Spikes, non-Scarf sets are too slow for the faster-paced metagame and vulnerable to most wallbreakers while Scarf is really easy to play around due to the lack of an actual spammable STAB and doesn't even check wallbreakers like Kyu-B and Garde that well since they both live Flash Cannons from full; all of these have become more noticeable as of late. We figured that, though it had gotten worse, it was still firmly enough in A+ rank in the first place to stay there despite unfavorable metagame trends. Still, if you feel like it deserves to drop, feel free to comment on it.
Finally, my thoughts on the current slate :
Serperior rise wouldn't be so much because of the metagame getting more favourable for it as people finally realising how brutal it can be. It simply decimates a lot of balance teams, its grtea speed putting it above a lot of the faster stuff you see on balance, and it has a really limited pool of actual anwsers. One metagame trend it actually like a lot is the huge popularity of Spikes which it absolutely loves since they severely wear down a lot of its checks. Its vulnerability to faster threats like Weavile and Torn-T is a pretty good argument against it rising, however, it does get access to Glare to severely cripple them, and the fatc that it sets up while attacking forced the opponent to be very proactive, which makes these kinds of predictions way easier
Hippowdon has been summed up pretty well by Vertex. Using Hippowdon kinda forces you into passive,defensive builds which have been getting rose recently, whereas Garchomp or Lando-T, while not beating nearly as many things, give you way more teambuilding freedom. It's not that hard to overwhelm offensively due to how much it's supposed to check, it's also quite easy to lure with stuff like GK Thundurus and Toxic Manectric. It doesn't have any move that's as spammable as say, Ferrothorn's Leech Seed or even Heatran's Toxic, and it's extremely one-dimensional, both of which which make it easy to consistently respond to. Unlike any other exclusively defensive Pokemon in A+ it's affected by Poison, the bane of most walls, which makes it pretty useuless against TSpikes teams if you don't have a hazard remover. All in all, despite how much it walls, it has way too many flaws to stay A+ imo
Empoleon probably shouldn't share the same rank as Gastrodon and Slowking. Having SR and Defog is nice and all, but beyond that it really doesn't have much worth using in its movepool, and running both Defog and Rocks on the same Pokemon isn't really a great idea in the first place, especially when said Pokemon has no reliable recovery. A lot of the stuff it's supposed to beat (Manaphy, Clefable) it really can't do much against besides Roar which can easily backfire in last mon situations, it kinda relies too much on Scald burns to threaten its checks, overall it's just not that great.
Gothitelle and Raikou I already discussed in the old thread. Goth should rise for basically keeping stall functional. Raikou should rise for its CM set and no other, it's a great answer to Electric- and Water-types which fits just as well on offensive teams as it does on balanced ones.