Yeah even with super easy Distros like Bodhi. I would recommend watching this project Discorkie and even reach out to the DeV there. As his standalone app for Windows may work on the older window versions and as it doesn’t load html, Js, CSS from what he has said in that thread.
It may give support to still access the forums with these old OS. It is a multi discourse.forum interface that gives a bit of a discord feel.
On Linux it is available as a snap & flatpak. So the app may have all dependencies more or less built in
Being hosted not sure but not likely supported due to not being able to guarantee security and such. So likely would need to be self hosted.