Without getting into the merits of Urban Meyers, he does say in the article that it was in response to the NFL rules on vaccinated and unvaccinated players that he made this decision, not the vaccination status itself.
The NFL has insane requirements for testing unvaccinated players daily and forcing them into two week quarantines. Vaccinated ones are tested weekly. So the point was that unvaccinated ones were more likely to miss training, games, etc because of the NFL’s own requirements.