Not the OP, but I just left the theater and really enjoyed it. Not the best Pixar film in any sense, but the themes really resonated to me, as a kid with immigrant parents.
It really did a great job evoking the themes of the sacrifices our parents made coming into a new world, the apprehension they developed towards the people already living there, and trying to blend the difficulties of maintaining old cultures/values while growing up in a completely separate ones. I saw that the director, Peter Sohn, had Korean immigrant parents, and it really felt like it was a story of his struggle.
I agree that the trailers were absolutely atrocious and didn’t made any mention of the things I listed above; if my girlfriend didn’t want to watch it, I probably wouldn’t have gone. However, I’m glad I did and even shed a few tears at the end