vince never actually rejoined WWE, he got extensive reconstructive surgery on his face and now operates as "tony khan" after he was betrayed by paul. the current "vince" in WWE is a body double. notice how "tony khan" nowadays looks completely different compared to earlier photos of him around the time AEW started. the real tony khan quickly disengaged from the wrestling business after he realized he was in over his head. the reason "tony" has been acting so erratic lately is a combination of vince's usual unpredictability and him finding that shit hilarious.