We see it happening more and more each year. A quarterback achieves a high level of success, only to have a highly ranked freshman come in the next season with a lot of potential and unseat them as the starting QB. Louisville experienced this earlier in the season with Jalen Hurts, and Tua Tagovailoa, as the latter was named the starter for the season opener.
History has now repeated itself with Kelly Bryant, the star QB at Clemson. Bryant led the team to the college football playoff last season after replacing Deshaun Watson. He looked like he was going to be the guy for the long haul, until the Tigers received a commitment from the #1 player in the 2018 class, Trevor Lawrence.