I help run the OpenToAll CTF team - while the primary focus for most are CTFs, the community (>500) has really expanded, e.g., (in the slack workspace) we have active channels for N-day repros, bug bounties with internal competitions, financial trading shop talk, and hardware hacking. You wont find much OTR or blackhat stuff ( due to slack ToS), but Ive found the community loves learning and discussing all things sec.

It doesnt hit your mark completely, but hopefully its somewhat helpful