I actually think I read that on Byrne's own forum. First he told them he just wanted to work on Superman reboot or not, then management said they were gonna bring back Kal-L, then they asked him to do his own thing. If I wasn't lazy I'd try to search for it. Either way I know Byrne was heavily influenced by George Reeves, who's season 1 Superman was in the Golden Age mode before it became very kid friendly.
I could be remembering it wrong though.