ANTi will most likely flop, but I don't think she's over.
Rihanna has never been an artist that has a solid fanbase and devoted people to where she will sell good without having radio shoved down the public's throat, and the good thing about ANTi flopping is that it'll prove this so her fanbase could stop trying to act like it's not true.
But I mean, Rihanna can still easily get more hits. She's young, she's generic, and I doubt she's moving out of doing Pop Radio candy. Soon as she gets more huge hits she'll be in a good spot again.