I have not been an Alpha tester, so my opinions are only based off of my prior experience and knowledge of the successes and failures made by Devs of other games in this regard.
The Op's topic "I would not want any human or alien AI in this game": This statement seems so very narrow minded, or limited in scope and vision. I know that this game was mentioned earlier, but it's worth revisiting due to it being the perfect example of why "no AI" is a bad idea. Fallout 76. This was a game that had a large marketing team behind it / AAA Devs / and a huge fanbase already invested in the Fallout Universe. (Granted there were a lot of issues and mistakes made by Bethesda aside from no NPC's), The playerbase felt that not having NPC's made the game feel incomplete, a husk of a game, and overall there was a general lack of interest due to the game feeling like an empty unpopulated MMO.
Atlas: Not a great example of NPC usage. They took NPC's and turned them into a hindrance to the overall gameplay. NPC's in Atlas are simply a player substitute and really don't add much to the game (speaking only about the NPC's that are owned by a company. Not the untamed wildlife or Ghostships which both add a ton of content to the game).
Ark: Great example of NPC content. Aside from what I would consider "taming abuse" (tribes having 100's of dinos that are only being used to breed and make more dinos which ends up killing server performance), the thing that keeps you going back to Ark is the NPC action. PVP is hit and miss depending on server performance. I LOVE PVP / full loot, etc. But there are plenty of nights when you get home from work and just want to do some PVE stuff. Or you're getting ready for a big raid or something and an NPC just kicks your butt that night. Jump into any Official server in Ark right now and tell me that it feels empty and not alive. You would be wrong, and lying.
I can completely understand the lack of NPC's at this point in game development. Game aspects and mechanics have to be rolled out in phases, and cannot be game breaking. If NPC's aren't in the pipeline until the core gameplay is solid, I don't think anyone could fault you for it. This seems like a game with a grand plan, and I am really trying to catch up and see if this is something that myself and my group want to jump into. I'd love another game to take up all of my after work time, lol. So I'm rooting for this game 100%. But I do think it would be a mistake to have a completely empty world because you're counting on a playerbase that won't notice because of the numbers. Take it from Atlas: no matter the hype you build at launch, if you create a game that you can't get people to want to play (in their case after so many development and community mod mistakes), it won't matter what changes you make. The 200 people left playing a game meant for over 60k players, won't care anyways.