People casually tend to forget that he's our only CB who has been available for selection for almost every game in the past 6 years. He's missed only 8 games (according to transfermarkt, seems about right) in the past 6 years. Rugani missed 11 last season. I don't even need to talk about the other CBs whose injury histories are pages long. But no, he's no big loss
If the management and he's having issues that can't be resolved, it's best for both to part ways. Especially with someone as emotionally involved as Bonucci. Just don't make it seem like he's a nobody to this team.