I'm sorry, but I think he's right. It's not good for either TVD or the program to leave after the Spring semester.
TVD would get about 3 months to learn a new system and get to know his WRs and that's not even as the #1. He'd have to start Fall camp as the #3 even if promised the #1 job. Otherwise, you destroy your team. Saban isn't going to anoint anyone without proving it on the practice field.
So, realistically, TVD would have at best 3 weeks rolling with the 1's if he could overtake the other QBs in 1 week of Fall camp which is unlikely. Saban would likely split practice snaps and name his starter the week after the Fall semester has started. Then expect 1 or 2 QBs to hit the portal and possibly quit the team during the Fall.
Regarding UM, it obviously hurts the program. They could have brought in a Transfer QB for the Spring if TVD transferred in January. TVD transferring after the Spring semester would put UM in the same position as Bama with a late transfer QB.
This story may have legs in that TVD spoke to someone on Bama's side, but when you look at it, it's not good for anyone.