I've been following this thread a bit, and I see a concern that isn't a practical threat to the forum.
Scuba Board as it exists and functions cannot realistically transition to a Facebook-based model, and I doubt any of the other listed entities could serve, either. Our discussion threads in a readily browsable and searchable format wouldn't exist there. Facebook is more 'chatty,' and given Twitter's historic character limit, I would think it would be, too?
The social media platforms listed are not a disruptive threat to the SB forum because this forum format is greatly superior in functionally serving the needs of this community. They become a threat when they offer a better way to do things...and they are nowhere close to that.
I think the basic idea is SB would have some content, or notification of with links to content, on social media to serve like advertising and draw traffic here, not move this community there.
While Facebook seems to be a lot of people's favorite dog to kick lately, much of the world is on it, and a presence there may get the SB word out to some people.
I get that some people actively dislike some social media platforms. I only know of Twitter what little I read of it, which makes it sound like a cancel cultural loving liberal wonderland that makes my conservative skin crawl. I wouldn't want to need a Twitter account to participate on SB anymore than some of you'd want a Facebook account...but it doesn't seem to be an issue.