Basically, there's no legal precedent. It's anyone's best guess.
We’re about to find out soon.
There's nothing prohibiting a crypto exchange from having a separate company to hold customer's assets. In a bankruptcy, the custody company should still be solvent. That's required in Japan.[1] Customers of FTX Japan still have their assets.
[1] https://www.coinfirm.com/blog/japan-crypto-asset-regulations...
You can't have the protections of "money" without the regulations of "money". As long as everything was going fine and government was still dragging its feet catching up to technology, the people who got in early got to pretend there was something special about cryptocurrency that made it possible to have their cake and eat it too.
Now, they're starting to find out why that's not the case.