Horizon 2's foliage system doesn't "crush" underfoot is the thing (which is weird, I would have thought they'd improve that in the second game given that so much of Horizon is about that lush vegetation, PS5 or not, albeit laying flat could be a problem for the foliage elements as I assume they are primarily 2D) There's kind of a light wiggle effect added to grasses when she passes over grass but it's not much, and Aloy still generally clips through leafy fronds; it's only the patches of tall grass that has full collision.
That said, even Horizon 1 had motion to all of its vegetation, so it's in there and it's in the second game. Looks like they messed up / didn't finish the ending of the Forbidden West Gameplay Demo (there's particles and flowing dust effects but then they didn't crank up the vegetation movement,) and I'm not seeing in either the Horizon 2 trailer or anything of Horizon 1 something that could really be considered a "storm" with like howling winds and turbulence in the trees (the closest I've found is her
riding through the whipping grasses overlooking Valley of the Fallen in Horizon 2, even Frozen Wilds is generally a nice day to go exploring...) So I'm not sure if that will change; they certainly spent a lot of time having the cloud system simulate chaotic weather so hopefully they have more motion planned for trees to match the new storm systems.