My theory is that the hooded man might be someone new who was also working behind the scenes, but didn't make himself known as Obito and Madara had done or could be someone already introduced as a part of the Uchiha, it could be Madara, or Danzo. So, perhaps even the masked guy isn't Uchiha.
So who do you think it could be?
He is Shin Uchiha
Shin Uchiha is a shinobi who was once Orochimaru's follower and also a test subject for genetic experimentation. He intends to revive Akatsuki and return conflict to the world so that humans can once again evolve through it. Despite his surname he is not truly a member of the Uchiha clan. At some point Shin became intrigued by Itachi Uchiha and began to imitate the Uchiha Clan, adopting their surname and customary clothing, as well as numerous Sharingan which have been implanted all over his body. His Sharingan-embedded right arm was harvested by Orochimaru and transplanted to Danzō Shimura along with some of Hashirama Senju's cells. Some time after this Shin left Orochimaru's side, taking most of his clones with him. His treats his clones as son as well as organ donors.
Some speculation say he can be Shisui Uchiha, his body didn't got found yet. He has the reason to hate sasuke because he killed his friend. Maybe Orochimaru helped him to get this eyes in his arm and head, as he done something similar to Danzo.
