This is in parts to remove the baggage that comes with the word, but also to be more precise in what is described here: https://i.redd.it/sm2tecjyuqf91.png
That's incredibly thorough. I guess I've not given it sufficient thought before.
Very calculated wording. Gives them a form of outs if the population realizes that it's actually just the US government generating fake "alien" stories to control the masses using sophisticated AI/AGI technology, they can then claim "actually we always knew it was advanced AI beings".