We have dropped that position with the rise of AI technology and decided to keep the suggestion on our then new feedback tracker for it open, but for a realistic chance to be implemented it not only needs to get into the top voted items, but in evaluation must also prove to be implementable with much more reasonable effort than it would have taken back then.
Eco is a game inherently made for multiplayer experiences, revolving around interaction with other players and while the addition of NPC's could improve the singleplayer experience, the resources necessary to implement that in a viable way so far would have been extreme and notably higher than for any other major feature so far - for a very limited benefit, as there is only a very small percentage of Eco players that mainly play singleplayer.