Hmm good point. If I could contribute to that conversation, the tag was more aimed for if the mod adds that adult content. I haven't explored what mods there are for games centered around drugs like schedule 1 (is it schedule i or 1 ?) but I guess if they don't add more variant or elements of the already existing drugs there would be no need to tag it with this new tag.
Or do add it for anything related directly to drugs/alcohol , it's kind of like every mods for stardew valley having SMAPI tag because it's the base element for modding the game, or bepinEX, for unity(?) engine games, let the users and forum moderator clean up the tags enabled ¯\_(ツ)_/¯)