The mouth looks kinda different. Can't tell from those shots.
What kind of color changes does he(?) have? Lighter with distinct barring? Color in the dorsal?
The actual ID will have little bearing on his fate to be honest. It's a large Mbuna. It's gonna act like a large Mbuna. If the color never gets much better, and it acts like a bully, you should take the fish out. No point in having an uncolored dominant fish.