Getting on an alt to post this so I don't get banned for disagreeing but here's my take:
I don't want to get into the debate of whether or not people are justified in thinking "trap" is a transphobic slur, and I honestly don't think anyone can convince anyone on this, but regardless going on a site-wise purge of old works is just not a good idea. I doubt anyone, when using trap in translations, is actively trying to be hateful. I think a better solution would be to add warnings before clicking on the manga in question. It is a fact that many just don't consider trap a slur, adding a warning can allow people who consider so still enjoy the manga, while others who believe otherwise avoid it. Purges would just further alienate and radicalize people who disagree