I was just about to write something similar. Wouldn’t that just centralizing linking and give control to one website operator?
Discussion
If we want to promote nostr the protocol over clients, we could use links like client.domain/onboard/npub... and host https://github.com/fiatjaf/njump there, with each client provider putting their personal preferences for acceptable clients there. I would find it a nice gesture to link between clients, with the own client on top.