I don't see this lasting. He just feels out of place.
It's a categorically good decision across the board.
He hit a wall near the very top of the sport and the only way to be successful is to admit he needed new instruction. Spending time with Dede - who is arguably one of the best coaches in all of MMA right now - is seeing the forest for the trees.
I don't think there is anybody in the UFC today that wouldn't benefit from some time at Nova Uniao and Dos Santos is no different.