Similar here: Even though I was somewhat aware ssh could do some PKI magic, I didn't CONSIDER deploying it. But I'll try to get our sysadmins to use it. Having U2F/FIDO support seems like THE big bonus to me (also I'd like to replace that ancient HTTP basic auth on our intranet with something more user friendly and add U2F as well).
So huge thanks for the article!
OTOH, key deployment depends on the situation and size. We have a single office (=> no network bottlenecks), our /home lives on a central NFS and machines pull their users from LDAP. When I joined the company, after I got my account, I ran `ssh-keygen`, set my keyphrase and could connect to any machine. If someone quits, the LDAP user is removed.
Regarding TOFU: I think we have some admin.git which contains all machines, and their public keys are distributed from there. So no TOFU for us. With PKI this central repo of machines wouldn't magically go away, the script would be just someone else's/your's (and it would be technically cleaner).
Also, when reusing hostnames the deployment system could reuse the sshd keys instead of creating new ones.