I'd guess the threat model to include things like "How likely is this org to disappear from the face of the Earth?" and "How susceptible is this org going to be to outside influences that have priorities higher than the honest/accurate/timely reporting of vulnerabilities?".

The modern infosec scene has shockingly little in common with the old school cypherpunk / hacker scene, besides appropriating the aesthetics and lingo.

Many of the people in it are even pro-information-censorship, pro-government, pro-intelligence-agencies, pro-big tech, etc. They have zero concerns about proprietary software, they trust Microsoft, they trust Google/Alphabet, they trust their government.

In my experience talking with these types, many of the same ones hysterical about MITRE's taxpayer-funded contract ending have seemingly never ever heard of OSVDB - the idea of a community-run vulnerability database is foreign to them. They seem to believe that it's simply not possible for a non-government-funded entity to perform this kind of work without commercialization.

Offensive Security - the company behind the OSCP, OSEP (formerly OSCE), and OSEE - have their official, primary support through Discord first, their own forums second.

Some. Others are on Matrix. The type of people you're thinking of are either interested in secure development (programmers with a security interest) or cryptography. Either they choose wherever the project's chat platform is or it's discord typically.