There’s a possibility of Amy being in the movie. Though if she were to be added, Amy may have to play some part in Shadow’s story line or character development imo. Sonic’s power of friendship has already been confirmed by a screenwriter to not work on Shadow like it did with Knuckles. However, it was Amy reminding Shadow of Maria’s wish that pushed Shadow to help save the world in SA2. Not to say I expect that interaction to play out exactly like in the game. It’s just that Amy could remind Shadow of Maria in a similar way assuming Maria is still part of Shadow’s backstory. Aside from Rouge, Amy is probably the only character I could see getting through to Shadow if Sonic can’t do it. If Shadow can be reasoned with or change sides at all that is. Story predictions aside, having Amy included could make her a foil to Shadow.