He fell hurt after Disney let him go when Amber went out telling the world how he abused her, I'm pretty sure he'll come back if they asked though... He's Hollywood, and most of them are narcissists, so I find it hard to believe he'd pass that tbh
Now, would Disney even ask at this point?
Even if Depp wins in court, I'm not sure they'd take the risk... Although they did take back James Gunn after they treated him as dirt when his twitter history came to light.
All in all, can't really see a PotC movie without Depp being a success tbh