Communications (Internal) Some people particularly avoid subscribing to social media platforms (for a variety of reasons). As platforms proliferate (Twitter, Facebook, WhatsApp, Instagram, Signal, Telegram, TikTok, Reddit, Snapchat, ...) and move in and out of fashion (Usenet, MySpace) it exacerbates the challenges in having integrated communication, particularly when the platform is closed (either by design or by choice). My local District's Facebook page is open so I can at least view it (having bookmarked the page).
Email based communication also has inclusivity issues, if you are not on the list you do not see the information unless there is an accessible archive somewhere.
It can be useful to shield forums from the full glare of exposure to the WWW - but in choosing to limit access, either explicitly or by the choice of platform, it should be done after taking into account the negative effects the barriers being created will have on inclusivity.
I think this forum has got it about right - read accessible to anyone using just a basic web-browser, participation after identification using limited personal data.