Finale thinky thoughts! As in I like to make it make sense.

I think they went back to their original bodies, not the confederation ones. They were in the same clothes as episode 1. They hadn’t just been transported.

Rios wasn’t there either. But Q cosmic power, handwaving. I mean technically the Stargazer blew up so he rewound time as well. So being like “you back in your original bodies” oh and due to time travel “you two aren’t there” is just Q being Q

To be honest I think the only reason Seven got re-borgified is so casual fans wouldn’t then be confused how she was XB again after Q clicked his fingers. It wasn’t actually a necessary thing for Seven to be an XB in the main timeline