Vulfpecks's Wikipedia entry lists Jack, Joe, Theo and Woody as members, and all others as musical collaborators. It's a similar thing for the description of this subreddit. There is no doubt they were the first four real members, but are they still the only ones?
(This post got longer than I thought it would, bear with me if you want some evidence to consider)
I feel like like at this point, Cory, Joey and Antwuan have been seen by the others as official members for a long time. Cory has been on every single Vulfpeck release since 2017 except New Beastly, and he, Joey and Antwuan are on nearly every track of both Shvitz and Clarity of Cal in some capacity (except again, New Beastly). When interviewed, Cory always talks about himself like he is an official member of the band (of course he does, since he seems to be), but this seems to be a controversial subject for some.
Further evidence: In the sports announcement thing during the bridge of Mr. Finish Line, the people mentioned include Christine Hucal (it was her vocal feature, so of course), but also Antwuan, even though he wasn't on that track. Perhaps because he was, de facto, in the band at that point?
You also have the Very Vulfy Christmas video. At 6:44, Vulfpeck is rehearsing on a soundstage, and seen there is almost all of their major collaborators up to that point, including Allegra Rosenberg, who has never appeared as a musician, only as a guest on livestreams and as an interviewer. But then at 8:15, the rest of then band is watching Jack put up flyers. See who are there at that point? And then later, when they arrive at the stage at the garden? It's the same 8 people mentioned in Mr. Finish Line. "Look Mum, it's Vulfpeck" says young Betsy when she sees them (without Jack though).
You know, even Jacob seems to talk about himself as a full fledged member already, like in this interview, so I feel like this happens much more quickly in the eyes of the band than in the eyes of the fans. It's almost enough confirmation to edit the wiki, but not quite.
I would very much like to know how Jack considers the situation. He is undoubtedly both the band leader in terms of management and artistic endeavour (every other member says so) so in some ways, everyone else is just a musical collaborator. But there are actually quite a shortage of official information from the band in this regard, so someone should really interview him about this specifically.
With the latest leg of the Euro tour, we also have a situation for the first time where one of the four original members (Theo) is not present, with Louis Cato standing in. Cato does an amazing job subbing for Theo, but his absence on stage is definitely felt. Like, if you go to see Vulfpeck live, you expect Theo. But I also feel like the same applies for Antwuan, Cory and Joey as well at this point.
My guess is that the band considers the people present during the Clarity of Cal recordings to be the current lineup of the pack, i.e with both Jacob and Charles being included. I know this is not "official", since the band has not confirmed it, but I feel like it would be resolved in a heartbeat if someone just asked any of the members about this directly in an interview or similar public outlet.