Not sure what happened but it was more than an open rumor that Garner never felt like Baron fully invested. Still a great talent but you wonder if he was worried that RG would favor other guys.
Moving from UT to Ole Miss and now L'ville seems to undermine the idea that it was purely NIL. As for "why L'ville?" It could come down to something as simple as depth and competition. He needs to play a lot of minutes and put up great stats. He needs attention. It won't hurt that the guys lining up across from him most weeks in the ACC won't be on par with the guys he's faced in the SEC.
I'm sure there are a lot of reasons both good and bad for him leaving. Maybe he wanted something new also. L'ville is a nice place within reasonable driving distance of some cities if he wants to take a weekend.
No need to get hyper negative with these guys. They're making decisions based on the information in front of them. In some cases, I have no doubt that the coaches were blunt with their post-season reviews. Several were very likely told that the young players developing behind them were going to get their opportunities. Some would have had a big role for UT- not irreplaceable but a big role. This is a choice players have now that they didn't have before. They're on the bleeding edge of something new. There aren't enough examples to look at to avoid pitfalls. Let's cut them a little slack.