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.
The intent behind hard-coding the filter is making it so reactionaries have a much harder time creating their own communities on Lemmy, trying to make it so our tools aren't being used by reactionaries to organize. But it's relatively simple to remove and they'll just make their own fork with the changes, so ultimately it's gonna be fruitless.