Not that boxing is a particularly an ethical starting point, but 1995 is when Tyson was 'allowed to return' to fighting.
What I am positing is that if Tyson had never fought professionally before being arrested, and his first fight was set for 2022, the scrutiny would be completely different. Especially if those comeback fights had anything approaching the same profile that they did at the time.
The fact that Tyson is a celebrity in retirement nearly 30 years later is gross, but it's largely irrelevant beyond the fact that, while it's unfair, timing is important - Kyrie, Cannon, Trump, are all after-the-fact phenomena (Trump's arguable) - so it's better to get caught for doing horrible stuff after becoming indispensable.
Myers Leonard did a whole lot more than Kyrie[edit: to rehabilitate and show actual contrition] and still wound up out of the league, but that's the difference between being Kyrie Irving and Myers Leonard, and Mitchell isn't even on the Leonard level yet.
Also Mitchell's not being barred from college - he was dropped by the UND hockey team, but according to a piece arguing that this current situation is unfair and that we're all just being too woke about it, he was allowed to stay in school, and found his way back into playing hockey (albeit unpaid):https://www.collegehockeynews.com/news/2022/11/04_Mitchell-Millers-NCAA-Career.php
I would be willing to bet that there are many places of higher learning who would take him as a student, just not necessarily a student-athlete. And he's obviously free to find another job outside of the NHL.
Which is why my position is that it's hard to shake the feeling that his punishment is little more than being 'down here with the rest of us'.
The vast majority of the rest of us being people who spent a lot of time, effort, and energy getting really good at things only to have somehow found jobs that do not involve these things. Most of us without tormenting our peers, even.
He's 20. He can do something else for a living and go play in an am league on weekends - just like everyone else.