I dunno how to feel about this whole thing really. It feels kinda irresponsible for the caretakers of a world to just kinda say "Well were not going to detail certain kinds of content anymore we already established existed" I kind feel like its the responsibility of the world builders to detail the ugly bits of their world so there can be a shared expectation and baseline when one moves from table to table. Things like the 1e 'candy van' demon were.. unlikely to get used but also kind of were a safety net for GMs and players in that it existing and being detailed meant that GM's didn't have to stomach doing it themselves.
Turning your head from the slavery thing just means putting the work on a lot of GMs who might really screw it up and make something actually offensive rather than just use the default that is provided and carefully measured. Same with a lot of things. Having it written down is a safety net for a LOT of people GMs and players included. Not providing that is, in my opinion, irresponsible.
Things should always be more fleshed out, not less. The creator should never bow to pressure to veil or hide something just because it might make a few people uncomfortable. Art is not supposed to make people comfortable after all. Art can never truly thrive and be vibrant when created by someone afraid of what people might think when they see it.