You assume that the server already knows the key though? The assumption was that it is the first time they connect. Which if so would mean that the key was con

You assume that the server already knows the key though? The assumption was that it is the first time they connect. Which if so would mean that the key was configured out of band, but if we add that possibility you can do the TOFU out of band as well. Yes, it is more common to transfer keys out of band - but it is getting a bit contrived.