As the topic came up on the ops mailing list.
It would be both an improvement in convenience and security to add network devices fingerprints to https://config-master.wikimedia.org/known_hosts
However the server's one are collected by Puppet, which is not possible to do on network devices. That said, they change less often than servers (upgrades or replacements) so a different approach is possible.
For example having a script that fetch the list of network devices from Netbox, with both their primary and management IP/FQDN (if different) and updates a static file (ran as cron where the current file is generated), Hiera variable, or Netbox custom fields.
Any change would be signaled, either via email if updated automatically, or prompted to the user if ran manually for verification.