Is their TOS legally binding in any way?
Yes and No, since you said "in any way" I'll try to explain.
all legal agreements are subject to the laws of the govt with jurisdiction, it gets a bit more complicated when a company has international customers at that point there may be multiple govts with jurisdiction in general there is a respected hierarchy: criminal cases go first, civil cases follow
Bankruptcy is a civil matter, it is being handled in Japan however the USA is considering criminal action, allbeit low-level (not murder), so for now both will trot along on parallel lines.
The terms of service should tell everyone what the company is, responsibilities for all parties, and expectations for everyone.
If the terms are considered by the court to be illegal or unfair the court will strike it down, for example I think I saw something that said the user is responsible for the security of his own username and password on the site, that statement could easily be construed many different ways in court if accounts are hacked. But if it seems unlikely that any hacker could break into 20 different accounts individually on the same day without breaching the site's security then it would likely be ruled against MG.
In short, if the law specifically covers it then that's it (this is rare), if the law indirectly covers it then a lot depends on how the lawyers argue it (this is usually the case), but if the law doesn't really touch it then you ask yourself what would 12 reasonably prudent people think is fair (this is not so frequent).
