If it also generated a relay list and a URL that you would click and it would open a client with your nsec already set up there ready to be used I think this would be perfect.
Maybe instead of prompting the user to assign a name you let the person who invites to pre-fill their name for them. So if I'm inviting Bob to Nostr I just give him a link that already sets his name to Bob. Once Bob is using Nostr they can change their name as they please.
Perhaps they don't want to be doxxed from the get go. We all know there's a good chance that what's in the nostr might never be erased. But Iris.to has a good solution. It assigns a random name (adjective+noun) to each nsec when they onboard. You can change the display name but the funny one remains.