If you look closely at Neji's symbol as a kid and as he is now before he died, his mark has changed. Maybe he unlocked a new stage for that curse mark.
Fail.THAT CURSE MARK HAS NO STAGES FOR GODS SAKE.If he is revived he won't be able to use his Byakugan because it is sealed.That seal activates when he dies and it makes his byakugan impossible to activate, which means it seals it.
Are you serious ? -__- The mark on his forehead is gone, because it destroys the Byakugan so other rival villages won't steal the secrets from it and the Main House controls the Branch House with it also.