Another meaning that has started to become prevalent is the conspiracy theory that some people don't experience qualia and have no internal "souls", i.e. they don't actually exist they are just robots. See twitter every time someone points out that some people don't have an internal voice or can't see images in their mind. There will be a chorus of people who are genuinely horrified and claim that this means that the person is not a real human but actually a robot. It sounds dramatic and I think people might even downvote me for this comment, but I've seen it quite a lot and increasingly often

NPC has, for some, become a term to completely dehumanise, in an almost moral panic kind of way. In a way that's like "what if the people I know are actually NPCs?"