Does anyone know why she never came back to the Mission Impossible franchise?

https://www.reddit.com/r/movies/comments/bun5or/actors_and_filmmakers_whose_careers_are_dead_and/ephv58y/

She had a prime role in M:I-4 and now she's sort of nonexistent.

My theory, and this part is race based, is that Hollywood can't have more than one light-skinned black woman in leading roles at a time. Only one IT girl, you know? Right now it is Tessa Thompson. But Paula pre-dates her by a few years. Then, I think her relationship with Robin Thicke and the coke soured many people on her.

Was there something else?

Rebecca Ferguson is vastly superior anyway.

Supposedly was approached but couldn´t fit it in due to scheduling conflicts. After watching Ghost Protocol again, I think its a shame she couldn´t come back.