I think that everything will be legal, but only payment for the rent will be made not by the fiat, but by tokens.
Then there may be a question about the official circulation of these tokens in a particular country.
Yes, it will be a very important issue for developers. In many countries, tokens are banned, which will not allow the project to develop without Fiat.
You can't keep any token from circulating in any country. You can crack down on people or companies located in a certain jurisdiction, but how would you stop a token from circulating?