I was waiting for Captain Cankles to come up. If memory serves me right (and just having forgotten about Horford makes me include this caveat), Bielfeldt was told to explore his options for his 5th year. Moe had agreed to come to Michigan but hadn’t signed his letter and Beilein was still waiting on a decision from Jaylen Brown. Austin Hatch was still under athletic scholarship at the time.
Before Beilein evolved in his recruiting (so, pre-Tyus Battle), he didn’t oversign. The only window when Michigan may have wanted Bielfeldt to come back for his 5th year would have come after Brown chose Cal and after Hatch became a medical scholarship. By then, Max had moved on and was comfortable transferring to IU. Props to him for having a great grad transfer year.