It's probably worth adding that IRC is so simple to stand up and requires such tiny resources there could be many independent small IRCD's running for smaller organizations and we would never know. I can't be the only one that got tired of drama from some circles of people and stood up my own semi-private nodes for a few circles of my friends. NGIRCD can be configured in less than 5 minutes counting obtaining a LetsEncrypt certificate. Services can take a few more minutes. UnrealIRCD is more feature rich but takes a little longer to configure optimally. I've personally taught many people how to set up NGIRCD. I have no idea how many of them kept one running. Slap a web front-end on it [1] and the bar to access is significantly lowered.

[1] - https://news.ycombinator.com/item?id=41201487