I've bought a coffee as well.
As to federation, no Kbin hasn't really taken any stances yet, but that doesn't mean they won't in the future. But feature wise, Kbin is so new that nsfw specific features could be a long way off. I doubt even @ernest knows as I'm sure his life has been thrown a real curveball this month. If we're still here in a couple years and there's no extra nsfw features, then it's reasonable to ask what's up. Right now though? There's so many missing features that you couldn't realistically even list them all.
They can't do a hostile take over of ActivityPub. The trap is that they would come in with open arms and an army of developers. ActivityPub maintainers would at first welcome the help and guidance from such an experienced team. Then, once they have the community hooked, they spring the trap and start making changes that are actively hostile to small sites. The community flocks to the big site because everything works better there, and the dream is dead.
Now maybe it'll never happen, but it's hard to tell. Even if Facebook joined with the best intentions, that doesn't mean the project isn't going to be taken over by a power hungry manager later who could still activate the trap card.