That's because the "rule" of !196@lemmy.blahaj.zone is to "post before you leave"... That creates a lot of random posts that all have some kind of "rule" in the title. Sometimes these posts get popular and you see them in your feed.
Every Rule post, including this one, provides clues to the nature of the underlying RULE. Once somebody actually figures out what the RULE actually is, it is posited that the fediverse will instantly disappear and be replaced by something even more bizarre and inexplicable.
There is another theory which states that this has already happened.
The very first community I blocked - let those who enjoy it do so but I do not. Unfortunately, the Fediverse shows you everything by default rather than things that you more or less want to, so blocking communities lacks the negative implications here that like blocking someone's phone or email address would elsewhere. So like if you want to block sports, you have to do so for every single team, league, and even type, plus all the new communities that continue to be made in the future. This is just the Fediverse's normal.