Unfortunately, no movies or characters were confirmed alongside the announcement, though it's hard to imagine the likes of The Incredibles, Monsters Inc
Are these official Lorcana cards
The Lorecast event brought us the news of Set 4 Ursulas Return, plus a bunch of other news
Additionally, Cinderella, Melody Weaver, has the Beautiful Voice ability - which gives any of the players other characters with the princess trait a plus one to their lore gathering ability whenever Cinderella, Melody Weaver, sings a song - thereby giving players even more of an incentive to use this character to sing songs for free
In a metagame where graveyard recursion strategies like Amber Emerald Dogs are everywhere, this is a massive advantage because it prevents the opponent from simply bringing their threat back to life the following turn
Your best bet for pre-ordering Rise of the Floodborn will be your local game store