The child is bound to have daddy issues galore even if the Vickers stop fucking with Ethan. His father is one of the most hated people on the internet, there's a record of him saying the most reprehensible shit imaginable, and to top it all off there's a fucking sex tape that he leaked of his mother and got convicted for. There is no chance in hell that Ralph and the Vickers will ever be on good terms so why even bring that up? In any normal family situation you'd be right, but that just is applicable here.
Hopefully Xander never meets that fat piece of shit and Faith finds a decent man that he can call his father.