I've never been into Pokémon (while enjoying other anime), but in my opinion the trailer is a mixed bag.
There's a lot you could criticize about it, for instance the unnecessary blackwashing (which you're not allowed to say but it strongly reminds me of what they've done in the Netflix adaptation of Death Note) , then the hyper realistic Pokémon. I mean, Pikachu looks okay. But Jigglypuff and Psyduck?
They're literally nightmare fuel.
Reminds me of those horror paintings from several years ago haha
However, I think the movie may be able to get a pass from hardcore fans, primarily those who were obsessed with it in their childhood or still are. In general I've noticed that more 18-25 year olds are interested in Pokémon than kids. I doubt it's gonna be enjoyable for most children nowadays, in particular because I think they all dropped Pokémon for Fortnite and other things. Even my 10 year old nephew says it's boring.