Hetzner did something similar a couple of years ago, suddenly disabling 1000 Solana validators that were using their service:
https://www.theblock.co/post/182283/1000-solana-validators-g...
https://www.theblock.co/post/182283/1000-solana-validators-g...
It's pretty clear they basically prohibit everything related to cryptocurrencies, even content, as you can see in their T&C.