I wanted to wait until I actually made reqs in a suspect ladder without choking or getting haxxed out in the final series of games before posting my thoughts, but I figure now that I got it I’d throw in my thoughts/experience Gray Fullbuster here. Keep in mind I'm going to moreso try to elaborate on my own observations, earlier posts mention the core arguments for each side.
The main thing I feel about Weavile in regards to the ban argument is that in the context of the current metagame he’s a very “Anti-Meta” pokemon. If you look at the
UU viability ranking list you’ll see that Weavile’s dual STAB combination gives him neutral or super effective coverage across just about everything in the A+ to A- ranking. Furthermore, a few of the exceptions (particularly Cobalion and Primarina) can be hit by its coverage moves of low kick and posion jab, respectively. On paper, this should clearly mean that Weavile has an overcentralizing advantage over the tier, since it can neutralize most of the top UU threats. However, I find this isn’t necessarily the case in practice.
I used Weavile in a couple of my Bulky Offense and VoltTurn team builds, and I generally noticed that other teams that used Weavile mostly fell into these two categories as well. Breaking these two builds down one at a time, on BO Weavile’s main role is knock off spam across the game and ultimately clean sweep a weakened team late game. While extremely effective at the latter purpose if the enemy team has been sufficiently weakened, the problem I found using Weavile is that unless your bringing him in after a sack, utilizing Weavile on BO entails a major prediction game between you and your opponent, and with its defenses and typing this means that you must predict perfectly or risk losing it altogether. I sadly forgot to save the replays, but these are two scenarios that occurred in two different games where I faced Weavile on the enemy team.
Scenario 1) Weavile comes in after a sack against my scarf Hydreigon. I predict the icicle crash and switch to Z-coba, he predicts this switch and goes for Low Kick. I lose Cobalion, revenge kill Weavile, but ultimately lose the match because late game Z-Coba sweep was my wincon against his team
Scenario 2) I bring in scarf hydreigon against starmie. My opponent switches into Weavile predicting my Dark Pulse, since Weavile can apply a lot of pressure to my team. However, I note his aggressive switches from before and decide to make a risky prediction and go for fire blast. Weavile goes down and my opponent ultimately loses because late game Weavile sweep was his wincon against my team
Bonus Scenario 3) SKIP TO TURN 46 IF YOU DON'T FEEL LIKE WATCHING RIVETING STALL VS. STALL CONTENT. Weavile comes in on my doublade, since my opponent correctly predicts me to go for toxic like I would against his Quag or Alo. He predicts me to switch out and goes for pursuit, but I predict this since he's pursuited my Blissey twice (that and I calc'd I'd live a Banded Knock Off at that health) and go for iron head. Weavile dies and at that point the game is over because Banded Weavile was the only thing that could potentially break my core.
http://replay.pokemonshowdown.com/gen7uususpecttest-640490632
VoltTurn, on the other hand, is where Weavile’s strengths shine the most. Being able to bring in Weavile on a switch without risking poor prediction to punish the enemy team with STAB, setup, or coverage attacks can make Weavile absolutely deadly in this setup. However, Weavile also serves as a major weakness against enemy VoltTurn teams thanks to four common members of popular VoltTurn cores that can check it (ranked from worst to best):
4) M-Beedrill: While a weak check that can only be brought in after a sack and can only work if Stealth Rocks are off, M-Bee can survive an Ice Shard from full and threaten the enemy team with the most powerful U-Turn in the game
252 Atk Choice Band Weavile Ice Shard vs. 0 HP / 4 Def Beedrill-Mega: 186-220 (68.6 - 81.1%) -- guaranteed 2HKO
3) Infernape: While it doesn’t appreciate coming into a Knock off and losing its item, the combination of Weavile being weak to its dual STAB along with potential U-turn, setup, and coverage options from the infernape means that the opponent is put in a major momentum disadvantage.
2) M-Manectric: With intimidate, a higher speed tier, and access to flamethrower/overheat, the Weavile users only options are to either switch and lose more momentum or ice shard for minor chip and die
1) Scizor: Previous posts have already gone into detail about how Scizor functions as a check/potential counter depending on setup, and its ubiquity in the tier since the UU Beta is well known at this point.
As a final point, Weavile’s susceptibility to all forms of entry hazards (especially stealth rocks and spikes from Klefki), hasn’t been brought up yet for the anti-ban argument. Granted, there are plenty of hazard removal options (the aforementioned starmie can make a decently good pairing), but any player worth his salt will take efforts to reset, spinblock, or taunt defoggers in an attempt to keep hazards up permanently, ESPECIALLY if they see Weavile on the enemy team preview.
TL;DR: Weavile is a top-tier offensive threat that effectively pressures other major threats in the metagame and can be absolutely brutal when used on VoltTurn teams. However, the plethora of solid checks and a few potential counters in the tier, requirement of good prediction and/or use as a revenge killer on BO, ironic susceptibility to enemy VoltTurn cores, and weakness to entry hazards means that there are plenty of counterplay options against Weavile. Unless I encounter something that drastically changes my mind over the course of the next week, I’m leaning towards
NO BAN in this upcoming suspect.