That's assuming they do not properly destroy their data, which they are legally obligated to do as far as I understand. You could also just encrypt your data before uploading.
Says who? Do their ToS even address what happens if they're bankrupt?
It sounds like Apple can legally do whatever they want if they go bust: https://law.stackexchange.com/questions/30810/what-happens-i...
I expect the same is true of all the other major cloud providers.