It seems from the outside that he does try and reach out, since starting the tradition of inviting former players to comes out with their families in the spring as practice winds down for the barbeque and what not. We don't know exactly how that is coordinated, but it definitely does not seem like they are being shut out at face value.

I have not seen both practices, so I can't compare or refute what Buck says there, but it does seem Bronco tries to involve former players. If Buck stopped getting invites because he was critical then that is BYU or Bronco being overly sensitive, if Buck just choses not to go because he is jaded, then on him. Interesting perspective either way.