They wouldn't oust her, but in true Disney fashion they'll find a way to nudge her around until she makes up her own mind which I bet is happening now. The sequel trilogy was a travesty just from a competent story telling point of view, she deserves to go just because of that.
Whomever takes over needs to "save" the brand so-to-speak. Disney has their own numbers for sure, but I'm willing to bet they can detect the loss of enthusiasm for the brand which is measured in things like toys, stickers, books, pencils and everything with a Star Wars label on it.
The positive thing is that it's not a damaged brand just the enthusiasm is down on it. Just look at the Mandalorian. Give the Star Wars space quality content and it's devoured. Star Wars is deeply set in our our cultural zeitgeist. You can easily reinvigorate it.