Although I think they had their fair share of genre diversity pre-Fancy You!(e.g: Deja Vu from What Is Love? album being literal dubstep like wtf), I think it's fair to say that they've been exploring many different genres lately.
Like in the past 2 years alone they've explored future house(Better, Believer, Kura Kura, Feel Special, M&M, etc)
Latin Pop - Hell in Heaven, Firework
Bossa Nova - Alcohol-Free
Synthwave/synthpop - I Can't Stop Me
New Jack Swing - Sweet Summer Day
City Pop - Say Something
Band(?) - Don't Call Me Again, Shot Clock
R&B - 21:29, Handle It
Funk-like kinda EDM(?) - Hot, Turn It Up, Scandal
And probably alot more I can't name atm.
Actually I think it's fair to say that More & More(album) and Eyes Wide Open are probably their most diverse bodies of work so far.
Literally who cares about whether or not TWICE are flopping when they're releasing the best music of their career