So I now looked at the video on my PC, frame by frame, and yes it is 60fps, but the stuttering I saw is real. some frames in the trailer are duplicates of sort. I say "of sort" because they aren't 100% identical.
these 2 frames here come right after each other for example:
the only difference between these 2 is that the second one seems to be EVER SO SLIGHTLY zoomed in compared to the first frame.
this happens on several occasions across the trailer, and that threw me off watching it on my phone screen earlier. I saw constant stutters and thought I was looking at a lower framerate footage
it does seem to target 60fps tho. which makes it weird that they aren't advertising it more in the ads and their official posts.