If the ladder is updated I haven't played any games on it since the tier update, but just by looking at the changes they seem to have a pretty big impact on stall on paper. Losing Quagsire blows chunks for sure, as does the loss of Drapion for TSpikes stall due to its stellar role compression abilities on the archetype, but the loss of Machamp and the gain of Mega Audino, combined with the loss of Meloetta from a few weeks ago, are both really big things.
Machamp severely restricted the way that stall was able to build; it basically mandated the use CroTomb or physically defensive Sableye (generally the former) to prevent it just 2HKOing everything available to the archetype in three moveslots. Spiritomb has lot pretty much any purpose it had on the archetype now unless you still wanna use CroTomb as your wincon for some reason, and no longer needing to keep this and Meloetta in check combined with the newfound lack of Quagsire to counter CB Emboar variants and the introduction of Mega Audino to the tier is probably going to result in a pretty big shake-up with regards to the way that you are able to realistically go about building stall teams. Just gonna comment on a few Pokemon that are affected rather than proposing any kind of framework for now, although I'm probably gonna be messing around with stall a lot in the next few days (prolly after the Veil vote) to see if I can get a working build in this new metagame.
Pyukumuku obviously benefits from this; it loses its competition from Quagsire in the Unaware slot, now only really competing with Ditto as the means of preventing strong setup attackers doing a number on stall teams; the inability to really do anything vs users of Taunt and Sub is a bit of a downer, but when paired with stuff like Golbat or Roar Steelix which can counteract this in particularly dangerous cases this isn't
that huge of a deal. Definitely still functions best on aggressive Protect+TSpikes stall builds, maybe alongside smth like Roselia which can keep stuff like Rotom-C or SEdge Virizion from being a bastard while absorbing TSpikes and setting them on its own.
The other Pokemon that loses a member of its competition on stall teams. Being generally useful for its ability to help with PP issues still dealing with particularly setup attackers that lack Sub and hit themselves very hard–see: Vivillon, Barbaracle, Turtonator, ZHB Virizion etc.–and consequently discouraging setup nicely, I'm sure that metagame conditions are beneficial to allow Ditto to thrive. Unlike Pyukumuku it isn't gonna be quite as dependent on the type of stall, but I reckon that it still faces very heavy competition from it just because of the fact that Pyukumuku is able to make quite a lot of teams very useless while it is still alive, whereas Ditto doesn't shut down
quite as many teams and is very dependent on what its opponent brings to a degree that it risks being very inconsistent if not put on the right kind of build. The other big thing it has over Pyuku is that it can be safely used alongside Vaporeon or Slowbro or whatever without stacking weaknesses, which is really big.
While losing the option of TSpikes when compared to smth like SpD Drapion, Skuntank does a nice job of replacing it in the Pursuit trapper role while retaining the ability to absorb TSpikes and having the option of Defog open to it, allowing it to either free up a moveslot for Golbat to use a full-on stallbreaker set or forming a double Defog core with it (more likely the latter) that makes keeping hazards off of the field a simple process that is flexible wrt situation. Band Sneasel is also nice just because of its speed tier allowing it to pose as a giant "fuck you" sign to non-Colbur variants of both Delphox and Mismagius on stall/semi-stall teams which make use of Eject Button or VoltTurners or whatever.
A nice addition due to its superb bulk and good typing/range of utility options. It shuts down Taunt Mismagius really nicely due to Gleam only 2HKOing at +6 (Rockium and Will-O-Wisp variants just get shut down by Pyuku, even if they carry TBolt/EBall for whatever reason, so only Ghostium/Colbur+Taunt really poses much of a threat) and makes for a nice Regen pivot pre-mega too. It also provides a new option for a wincon while pretty seriously surpassing its competition wrt overall bulk; CM+RestTalk+Gleam or CM+WishTect+Gleam both seem like fun for sure, and I'm gonna mess around with them defo. Between its cleric/pure utility set and its CM sets it has a lot of things which may work.
All in all really fun-looking shift for just about every playstyle, but I wanted to talk about stall for a bit 'cause unlike OU it's actually fun to play/build with in this tier lol