GGG wasn't with Sanchez nearly as long as Rozier was with Jacobs. GGG never had the relationship with Abel that Jacobs had with Rozier.
A fighter is allowed to leave a trainer. As long as he hasn't stiffed the trainer for money then it's not an issue.
That point isn't even valid being that Jacobs didn't even put in a winning effort in either of his two biggest fights. I could see if he went in, and left it all on the line, following Rozier's instruction with a full effort and still came up short, but that wasn't the case. He didn't listen to his trainer half the time, and also didn't put in a full winning effort in all the rounds of either the Canelo, or GGG fights.
Dont know if this is the case but as the saying goes.... Money Is The Root of All Evil !!!! Look what people do for $$$$$$$$$$$$$$$. Just look at the state of Sin City the Cess Pit of boxing. The days of honor & loyalty are over I'm afraid
Rosier seems like a decent dude. That said, I could never stand his nephew, Curtis Stevens. Of all his losses, I thoroughly enjoyed watching him lose convincingly to The Contender alum, Jesse Brinkley.