Trump never seems to go bust entirely. His business empire seems designed in a way that parts of the business fail leaving other people (the creditors) to carry the can. But the core business is legally innoculated from the failing entities (veil of incorporation, corporate personhood and so on).
What I mean by the core is the real estate business that has kept chugging along since his father's day.
Trump himself starts all sorts of businesses and nearly all of them fail. But Weisselberg seems to be the accountant running the core business. I think that is where Trump's wealth really springs from.
The way the indictment reads about the son's condo is poorly worded. I am not clear if it is a different one, or if he looks after the one his father uses when he is in town overnight. If the latter, this is surely a grey area of the law. As far as I know, it isn't illegal for a son to stay in the same place his father uses for legitimate business purposes. This is going to be a long argument about what the law allows. Usually, if the law doesn't rule something out, it's legal.
I could be wrong about this. I don't have the time or enthusiasm to do the research. The case is going to be all about complicated accounting definitions for allowable tax deductions. Both sides will produce expert witnesses. The difference with Leona Helmsley is that Weisselberg is an accountant and most likely will have thought about the deductions he is taking.