Not that it matters a lot, but Team Rocket came with Banjo, whose presentation was on the same day as Terry was revealedOne thing we will have to worry about in the showcase: Whether there are any Pokémon-themed Mii costumes. The presence of one would lower the odds of any becoming playable, since why not save it until their update? Would likely limit our options to a "super recent first party" niche at #11 or so, since they wouldn't have even narrowed down which game they wanted the newcomer from until...well, probably not until around when Fighter #9 is done.
Not likely we see a costume here since it's only happened once before (Team Rocket oufits in Terry's update), but...worth being wary of.
Appropriately enough, I've seen people talking about how a future trailer could start with the same setup as Sephiroth's, except with Dharkon instead of Galeem. It'd actually fit perfectly to have the legendaries do something to stun Dharkon and then beam down to fight the dark god alongside the other characters just like in the battle against Eternatus.
Could even throw in some extra thematic touches. Like Dharkon's power causing some of the puppet fighters to grow to giant size and loom over everyone, only to be struck down one by one with a flash of light in a single blow!