Many people commonly discuss Michael Jackson's nose when discussing nose jobs and rhinoplasty, in general. While I'm not familiar with the details of his surgical procedures, generally speaking, if someone's nose is operated on many times, and if the support structures of the nose are not respected and are removed too aggressively, then there's a possibility that the nose can collapse. The bone and cartilage that make up the support system of the nose are very important, not only for the cosmetic appearance of the nose, but also for the function of the nose.
So while we are able to get rid of portions of this underlying structure, we can not get rid of the entire thing. So, if someone has a large bump on the top of their nose, we can get rid of the bump, but we need to leave the bone and the cartilage that is beneath the bump because that's important for structure and for function. So, it's always better to be more conservative, and you need to understand that the nose is both an important cosmetic feature of the face, and it's also functional. So if a surgeon respects the tissue within the nose, including the bone and the cartilage, then a nose should not collapse.