I'm very surprised this isn't cross-gen+switch tbh.
Past-gen is starting to slump in sales, so it was probably easier to just commit full-stop to next-gen whether the game needed that level or power or not. (There's some nice physics of buildings crumbling and lots of people panicking in the streets, but everything looks scalable IMO, though the solid framerate in the trailer at least is a good sign.)
I could see them doing a second series of DAH2 releases with past-gen and Switch ports 6 months after the first release, or even just a Switch port. (The first game's Switch port came out a full year later, so they have time... but also, the Switch port of DAH1 was hit pretty hard in visual quality, so they might have trouble with DAH2 on it even if they only concentrate on that one post-launch port and don't bother with PS4 or XB1.)