Facebook has never had a consistent policy with what's allowed and what isn't. They haven't banned several obvious scams I've reported, but have banned a post that contains a picture of dog medicine (a blister of pills). The vague reason given was that it (could've been?) related to recreational drugs or something like this.
Nearly all of the LGBT groups that I am aware of are primarily on Discord and other, similar services for this very reason. All of the other socials exist only as on ramps to the real community. The weirdos can shout into the void all they like, but nobody's listening to or engaging with them.
This is also why I keep saying that the Discord model is the future of social media, not Facebook or Twitter. Turns out that when you can allow users to exert meaningful control over their social spaces, instead of relying on the judgment of some of the most sociopathic, self-interested and immoral people in tech, you can create actual communities.
Curious what it is about Discord you think is different enough from other social media to warrant this claim. I don't have strong feelings one way or the other, just curious.
Discord lacks the "capriciously moderated town square" that most other social media has, and this is a feature, not a bug.
Instead, it harkens back to the older era of web forums and IRC channels where communities were siloed and moderated by actual humans using moderation tools, permission abstractions, and even bot API's that are actually fit for purpose.
The key advantage that Discord has over the pre-social-media status quo is that Discord gives the ability for users to moderate their social spaces without the overhead of having to run their own forum software or intuit the arcane NickServ/ChanServ deep majick. The friction for creating a new social space is quite low, and joining one of those spaces is as simple as obtaining an invite - which can either be publicly posted or only handed out to specific users on a case by case basis.
Sites like Facebook, Instagram, and Twitter are antithetical to this - they want you to throw you in the deep end and get hooked by engagement-bait. Reddit was probably the closest prior art, but Reddit still gamified engagement using voting, kept the walls between subreddits very thin, and refused to give moderators adequate tools to properly moderate their subreddits. As time has gone on, further changes to Reddit's structure and userbase have turned moderators from being community curators to doing free janitorial work for a tech company.