The Chapo.Chat moderators have already stated that they're planning on removing the hard-coded slur filter from their instance of Lemmy; it's the reason you're not able to say the full text of ACAB. It's just a bad idea to have something like this hard-coded in, leftist instances are created by fostering a good culture and not by babying the people who run these servers and if we want Lemmy to grow as an actual federated alternative to Reddit then it's worth bringing up how bad this policy is by the original developers.
If you don't like it, fork it. I think if you want to say slurs there are image boards for that