So.
Fire emblem warriors.
What we know.
Full Confirmation:
"Almost all" are Archanea/Awakening/Fates.
Will include variety of weapones and classes.
Larger than standard (aprox. 16) starting roster for a first title in a subseries. So ballpark 20-24 depending on circumstances.
Marth, Chrom, and 4 OCs.
Weapon triangle and bonuses (bows on fliers).
"All but confirmed":
Corrin, Xander, and Lobster (first trailer).
Major Popularity Icons from Those Games:
Tiki, Anna, Lucina, Robin, Tharja, Cordelia, Donnel, Azua, Fates Royals (if the Heroes poll can be used as a reference).
Let's Be Real™:
are damn near locks. Popular as hell, Smash, and Amiibo.
Alm and Celica, part of amiibo, part of recency, part of being semi-tied to Marth's games, hold a significant chance.
Major Villains from Those Games:
Michalis, Camus, Gharnef, Medeus, Gangrel, Walhart, Aversa, Validar, Garon.
Just putting this out for roster theorizing.