Yeah, no indication of how many remade maps there are, but it seems like there might be one per emblem, so 12? The current guess is that they're special paralogue maps tied to the emblems. I mean, I hope so, map remakes are cool as a side thing, but I don't want the main story to have a bunch of old maps randomly thrown in lol.
Also, I really doubt this game is gonna be the standard 22-28 chapter FE story given that this is a big home console game. They were able to justify it in 3H because of the multi-route gimmick (even if it was mostly the same maps reused), but this game seems to be a singular route. Plus, I feel like we've seen waaaaaaay too many different maps at this point for it to be "only" 25 chapters or whatever, unless IS doesn't care about spoiling the entire game lol. We've seen some pretty high stat values too. In the Corrin vid the Halloween girl (Panettone?) has 71 HP for example.