So as @PP44 is saying, it's open source. The devs work to make sure that anyone can set it up straightforwardly to run with their own modifications, not just the main version -- and that means modifying the slur filter is also supposed to be straightforward, even though it's not encouraged. There isn't actual moderation on the whole platform per se, since two instances can federate even if one has no slur filter. There are lots of "points" to federated stuff, though, so the existence of a slur filter works well to help keep Lemmy from attracting the cesspool-types while still enjoying those other benefits.
So as @PP44 is saying, it's open source. The devs work to make sure that anyone can set it up straightforwardly to run with their own modifications, not just the main version -- and that means modifying the slur filter is also supposed to be straightforward, even though it's not encouraged. There isn't actual moderation on the whole platform per se, since two instances can federate even if one has no slur filter. There are lots of "points" to federated stuff, though, so the existence of a slur filter works well to help keep Lemmy from attracting the cesspool-types while still enjoying those other benefits.