Windows 10/Server 2019
The Microsoft port of OpenSSH is now part of the Windows operating system for Windows Server 2019 and Windows 10
https://docs.microsoft.com/en-us/windows-server/administration/openssh/openssh_install_firstuse
The core facts for ssh should now also look in the default Windows location for the host keys %ALLUSERSPROFILE%\ssh\... and populate the facts.
Recommendation from puppet-users
https://groups.google.com/forum/?utm_medium=email&utm_source=footer#!msg/puppet-users/-irkkbzrUZw/wPR9o8QHDAAJ