What is the worst that can happen if you put in an unused openssh private key with a caption "This is just a demonstration, dont do it for your keys"

I wrote a blog about using SSH keys to authenticate multiple accounts in Github/Gitlab. In that I created a new ed25519 openssh key. I demonstrated the public key you are supposed to copy. Also showed my private key that you are not supposed to copy or share with a note that I did it just for demonstration.

What is the worst I can expect off that unused key other than possible cringe?