Disney-Fox: It's done

[Star Ranger4]

The obvious solution would be to solve the Endgame movie with some kind of time-rollback shenanigan, 

Indeed, and something most Fan sites are hoping will happen.

Regardless, I will also agree that while Mar Vell hoped to re acquire certain movies rights there was no reason to waste celluloid on the possibility it would happen, the players involved are real politicitists of the highest orders.

Therefore, While time travel ret-cons are very much expected, they can not be confirmed.