It's a results driven business, with the added pressure of being the first. If it goes well, she'll be a trailblazer, knocking down doors. But if it goes badly, it could set the cause back years.
Playing for Rihanna wouldn't be a struggle for any pro player. Even if yer ain't familiar, you sit with the songs for a few hours and figure it out. No sweat.
The thing I noticed with RHCP is they call anything they noodle for a while a song. Then Anthony raps some stream of consciousness over top, do that a bunch of times and it's another album.
The Chili Peppers with Californication.
Iron Maiden with Brave New World.
Those two come to mind because both bands star had faded quite a bit by the time those came out, but they got relaunched into the limelight on the back of those releases.