tbqh, many people in /leftypol/ are accelerationists too. Especially leftcoms. It's not unthinkable that the FB page and /leftypol/ share their memes. In fact, the admins of that page may very well be members of the board... that isn't unthinkable either.
What's wrong with /leftypol/ anyway? There is a lot of autism, but there are many good posts as well.