I think you’ve got this a bit backwards. I could see adding the ability to capture people and sell them to slavers, since at that point it’s something you are doing to profit your character, and not just for shits and giggles. I could also totally see slaving beginning to happen in a post-cataclysmic world, and I could see adding something like becoming one yourself into the game, though it would almost certainly have serious repercussions on your relations with all of the non-slaver factions out there.
That said the progression here, if something like taking prisoners goes in, is going to be NPC slavers -> becoming a slaver yourself. Not adding the ability for you to take NPC slaves yourself and then adding NPC slavers into the game. And I’d also definitely like to see some meaningful NPC benefits/relations going on first as well, that way the fact that you are essentially declaring yourself scum to the majority of NPC’s has an actual game impact.
So I could see you having the option to become a slaver going in in the far flung future, but it’s a long way off, and we’ve definitely got some other things to go in first.
All that said I’d like to reiterate KA101’s statement that abusing slaves won’t be going in, even in this hypothetical future option your interactions would be largely limited to capturing+selling slaves. Also I don’t see control chips going in, the world of the future was definitely not one that promoted slavery, and something like that just wouldn’t be something you would realistically find in the US.