It's great they picked an actual actress for Zelda, but considering how badly they mischaracterised Peach in the Mario movie...? Yeah, they're likely to mischaracterise Zelda here, too - give her more action and importance than she gets in the actual games.
I mean, apart from Spirit Tracks, Zelda's never been a frontline character - her best role in Twilight Princess has her provide Link with information, sacrifice her life force to heal Midna, and then shoot Light Arrows at Ganondorf to stun him so Link can attack him. Ocarina of Time? Doesn't do much on-screen, either as a child (makes sense) or as Sheik (because the camera's on Link for the entire game). A Link Between Worlds? She sees where things are headed, so she gives Link one of the Pendants early so it's not trapped with her; then she's captured by Yuga, and gives Link the Light Arrows during his final fight with Yuga.
Even in the maligned and horrific BotW and TotK, her viewpoint is optional and easily missable, doing a handful of things in the past; Zelda has never been a frontline character, yet of course since this is a movie she's undoubtedly going to be more important than Link himself, with a hugely unrepresentative personality and characterisation to boot. Massively disappointing, really.