also, PKDNS is a consensus, which means that everyone has to follow it, or it doesn't work.

that's not how nostr works. nostr is only a protocol, not a consensus protocol. there is good reasons why you might not want to use the same protocol. like closed and private relays, companies will not want this information broadcast either, if it links to the company. the users directory events, though, are perfectly fine to be pushed and pulled from company relays if they decide to, it just leaks membership.