probably instead of trying to ask for age verification, they will most likely try to make 'nostr' look like a criminal zone or try to take it down once they see that the accounts, content and posts are not under the control of the clients.

either they will try to go against those who manage the relays by knocking them down without giving an explanation, or they will try to make laws to force users to give their private keys when they ask for it.

or they will do the same as they do with the forums where monero is spoken or used, they receive attacks daily to try to destroy the community.