I don't think BJ and Nick are "pals," but Nick and Nate have both helped BJ in training camp before (in Hawaii no less, so you know they blazed together) so they've always been cool with each other. You'll notice short of the kabuki theater at weigh-ins, both Nick and BJ shyed away from saying anything bad about the other fighter in all their interviews leading up to the fight. Nick had a poster of BJ in his room when Nick was coming up and BJ was one of his favorite fighters, almost a la Mirko CroCop to Pat Barry. BJ also called up Nick about the fight when it was proposed and they talked about it, so they're on good terms. Any kind of disrepect between the two was more then likely agreed upon kabuki theater to hype the fight. I wouldn't be surprised if BJ helps Nick train for GSP. Even if BJ does officially retire, I'm confident he'll still train.