It definitely shows some bosses we haven't seen before, and the narration hints at what the story might be, or at least the surface level that represents this character's narrative. For the most part, it's a bit like watching the original release trailer.

You don't need to watch it to know, it is fucking epic. I am hyped beyond all measure. We are so fucking back.

Yeah I stopped about 15 seconds in because it seemed to be showing multiple boss characters.