An issue like this is always contaminated by tribalism and bad faith perspective. United are a big club so many people commenting on this are motivated by their opinion of the club.
However, United’s standing in the game as an elite institution needs to come into the debate. What they do matters.
Footballing-wise you’d imagine there’s a motivation to get a talented player back in the squad. He’s also very valuable. Commercially, however, allowing him back may see sponsors walk away. Morally speaking - which should be a central consideration - it’s pretty straightforward. He’s done something very wrong.
In my mind he should be asked to leave the club. This stuff matters far more than having a good player on your books.