re: Shea says to not be surprised if Cai Bates doesn't end up in this class

That's not exactly what he said, and context is important. He said he wouldn't be surprised to see Nates flip, due to all the smoke surrounding his recruitment right now, he wasn't really making a prediction.
He doesn't have any insider knowledge other than the fact that Bates is obviously listening to what Tenneessee has to offer.

He then went on to say that with the transfer portal, the guys like 2 corners who recently committed are guys who are absolutely worthy of an offer, especially with senior season evals coming in, these guys are absolutely takes.

If they weren't, they would save those spots for transfers.

He also said the initial work that goes in to getting transfers to come to LSU is already underway and that LSU has been contacted about transferring in by a number of players already