Hmmmmm, I may have to defend Zendaya. Is she a mega A-List star? No, but in terms of her key demo, which is Disney's demo, she's one of the biggest stars they have. Her Disney Channel movie was very successful and I believe she is the producer of her upcoming Disney original series. It takes time to cross over, as it took years for former Disney stars to do so: Justin, Britney, Christina, Lindsay, Ryan Gosling, Miley. She's only 18, and seems to have a solid team around her that won't lead her down the path of other's post Disney mental breakdown.
As fas as that Aaliyah movie is concerned, that was a Lifetime publicity stunt that Zendaya was smart enough to get herself out of. The family didn't want the movie to made whether Zendaya was in it or not, they think Aaliyah deserves a feature film. Once the producers (Wendy Williams) couldn't get the rights to Aaliyah's music, Zendaya was smart enough to drop out. Look at who they cast for Missy Elliot and Timbaland, that movie would have done Zendaya more harm than good. Look at it this way, more people know Zendaya's name than the girl who actually ended up starring in that movie.