https://www.reddit.com/r/ltsc/ Did that quite awhile ago, I forget in response to what. I lost a lot of really great info on how to use Windows 10 LTSC / Server / Enterprise / IoT when r/LTSC went permanently private.
Couldn't you (request to) join if that's interesting/valuable to you? Or it went private as a sort of pseudo-deletion, and doesn't really exist any more?