I guess it depends on what you mean? I have yubikey 2FA on my servers for SSH, but also have SSH keys. I use SSH keys when I can, and yubikey when I don't have my SSH keys handy.
I suppose if you're doing yubikey+password auth and don't have any keys configured for your ssh client you're fine because... you don't have any keys? :)
I suppose if you're doing yubikey+password auth and don't have any keys configured for your ssh client you're fine because... you don't have any keys? :)