I'm surprised that some of you are actually EXCITED for these new characters. I'm personally not mad cause I kind of expected them to do this but you WANTED it? Do you not realize what this means? This movie will basically just be like the other, regular Pokemon movies in terms of its writing. A story focused on a legendary Pokemon in which Ash meets a few random humans at the beginning of the story who will sort of guide him through the plot but who no one actually cares about. The only reason this will be special is because we're already invested in this whole deal between Ash and Ho-oh. Nothing else in the movie will actually matter.
The lack of companions is probably good actually since they never actually do anything in the movies, but that doesn't mean these new characters will be anything spectacular. I would've preferred it just being Ash and his Pokemon alone, seeing him have a proper solo adventure for once. Also now we need to focus in giving them characterization and backstories, rather than fleshing out ASH's character as much as possible. They're probably just there cause they needed to promote gen 4 Mons anyway (if it leads to gen 4 remakes then sure Ill be happy but still).
I mean, MAYBE they'll pull some exceptional writing for these new guys, there have been a few memorable movie characters after all (namely Molly, Sam and maybe Melody), but their track record speaks for itself and the fact that they're replacing the classics isn't helping their case.
What'll make this movie for me is if we actually get to see all (or most, at least) of the Pokemon Ash caught in Kanto, and the fact that there seems to be actual 1v1 Pokemon battling in it (which is why Cross is the one character I'm welcoming, seeing Ash have a rival in a movie should be interesting. But again he should've been the ONLY important new character, to dedicate as much time for the rivalry as possible).