I find it hard to believe, mainly because the Navy, unlike the Army, doesn't attach a unit patch of this kind to their uniform. The only unit identifier, often not worn, is a rocker on the right shoulder. These rockers are only worn by enlisted ranks. This is also the only official SEAL team identifier I've seen, often "SEAL Team 5" or even just "ST5".
Considering Dick Marcinko's descriptions of Red Cell's later operations(after he was out of the group), I wouldn't be surprised if they wore patches. Read Rogue Warrior-Red Cell if you need a better explanation. I know his books are fiction, but he mixes a lot of truth in them too.