Vito was retarded for trying to come back
Did he honestly think he was gonna be able to go back into the mob life with them all knowing he's a homosexual? Especially with Phil being out for blood.
I find it hilarious he thought he could just waltz back in and say "I'm not gay i was on medication that messed with my head" him running and hiding out for months kinda told everyone he was gay.
If anything Tony should have told him to leave and that Phil was gonna kill him and never accept him being back, since Tony tried his best to keep him alive i'm surprised he didn't try and get him to leave.