It's not a new thing for a trailer to show an FPS spike in it.

I just did a quick search, and found this one: https://www.youtube.com/watch?v=xWrduBxozT8

A few clips in it show a drop in framerate. I was mostly just asking on the first page just to make sure my phone wasn't being weird and displaying it wrong. Thinking this in any way portrays the final product is just stupid.