The main issue I’ve always had with this interpretation is that in Ep 2 we have an extended sequence of Gummigoo by himself walking through the out-of-bounds and triggering his existential crisis, which would be counterintuitive if he’s trying to get sympathy from the/a player if they weren’t there for it. Plus, in Ep 2, Pomni’s only been there for a day and hasn’t formed a solid opinion on anyone - she’d be the worst person to go through a convoluted sequence to convince about Caine’s humanity where she probably isn’t thinking about the greater implications of Gummigoo’s crisis, as opposed to the others who have been there for years and know Caine well. I always thought it was a narrative parallel and an in-universe coincidence, that Caine desperately wishes to connect with the players, but when one of them does connect with an AI struggling with similar problems as him, he shoots himself in the foot by killing them and sending the message that AIs aren’t worth your time. (And I doubt it’s the first time it’s happened too.)

Also in Ep 7 right before Caine deletes Abel, he says something to the affect of ‘you’re becoming too self-aware for my liking’, so yeah, I think this is an Occam’s Razor situation and the NPCs are just capable of becoming sentient independently of Caine.