Would it be accurate to say that you want to sync group membership in Discourse with roles in Discord?
If so, I may be doing something similar for another client soon and there may be a potential for co-sponsorship of a Discourse / Discord syncing plugin along the lines discussed here: Discourse Trust Levels for Discord
I understand that you’re talking about syncing groups and roles instead of trust levels and roles, however the structure to do this will be the same, so co-sponsorship could work.