"BYU has some good backs right now but TySon would push it to a new level."
Judging from his film and stats, he appears to be solid, but not spectacular, and certainly not a P5 level RB1.
His best game last year was against Coastal Carolina, where he rushed 11 times for 81 yards and a TD. For reference, Coastal Carolina ranked 120th in run defense last season. The only other even slightly notable performances he had last season were against Vanderbilt and Texas A&M, where he rushed for 48 yards against each team, along with 1 TD against Vandy.
IF he comes, I think he'd be able to at least provide depth, but if you think he's going to come in and be a 1000 yard rusher and take BYU's run game to a whole new level, prepare yourself to be sorely disappointed.