There's a Matrix room for NNCP https://matrix.to/#/#nncp:matrix.org that's also bridged to #nncp on irc.oftc.net. It's pretty small and there isn't a lot of frequent activity there, but it's a good place to ask questions about the project or see what others use it for. jgoerzen hangs out there too!
I keep meaning to try building DNews, which is a single backend with NNTP, web and mail interfaces.
Matrix/IRC/Zulip/Slack are not fundamentally incompatible with Usenet so much as philosophically incompatible. It's the difference between casual mostly-realtime and expected delay.
