If I have your public key I could probe a server to see if it recognizes that public key. Which would tell me information you might not want to be leaked.

Github has public keys available, so the server owner could compare the key you sent to those - and that would identify your github username.

Whether that's a concern or not is an open question, of course.

All your base are belong to us. We recommend rotating keys more often than never.

l33t h4xx0r5