I'm not so sure whether Whedon was blatantly and purposefully alluding to Adam, but the divinity angle was pretty damn obvious and practically smacked me like a brick to the face.
Thank God someone remembers God.
I think what people mean to say is that his messianic behavior is still in line with Vision's personality, not necessarily saying it's accurate to the comics.
People are saying Vision isn't Adam because they think Adam is still coming via Gunn in GOTG2. If its not that its "Vision sounds like Vision, dude" which is nonsense, but I don't fault them because most of them don't know theology. I'm by no means an advocate for religion. I don't even go to church. Coming from a Greek Orthodox family I have basic knowledge on the matter. Again, more and more I'm starting to see how
younger people don't. That's fine, but it makes this particular discussion exhausting.
The same could be said about Ultron anyway, in which he's never had a god-complex and yet somehow adding that to his personality actually makes so much sense for his character. It was refreshing and his fixation over the Judeo-Christian God really added another dimension to his character unlike any iteration of Ultron that came before.
It was the best thing about him. Wish he'd gotten more screen time to explore it further.
Similarly, it wouldn't surprise me if Whedon alluded to biblical concepts such as being a messiah for Vision as means of countering Ultron's more destructive ideology; in which Ultron's beliefs was more akin to God from the Old Testament (Ultron's reference to Noah was an obvious hint). So while I don't think Whedon was consciously referencing Adam, I can see why he made such choices in re-inventing Vision's character since it worked as a contrast against Ultron's self-perception as a God.
This is where Adam comes in.
While it may seem like Vision was just being set up to be the anti-Ultron in the eyes of Tony and Bruce, its Thor who saw what was really coming out of the Cradle - which Vision clarifies himself:
"I am on the side of life. Ultron isn't. He will end it all. I don't want to kill Ultron. He's unique and he's in pain and that pain will roll over the earth. So he must be destroyed. Every form he's built, every trace of his presence on the net. We have to act now and not one of us can do it without the others. Maybe I am a monster. I don't think I'd know if I were one. I'm not what you are and I'm not what you intended. So there may be no way to make you trust me...but we need to go."
Vision is being set up to be the anti-Thanos. The Avatar of Life aka Adam Warlock, created to combat Thanos, the Avatar of Death.
Thor's vision of Adam solidifies his role in the events to come.
In this regard, I don't think they literally wrote Vision with Adam in mind. Rather, there's simply the huge possibility that Vision could already take Adam's role in the MCU, based on the way they had written the former in AOU.
I think Whedon set out to do comics Vision and somewhere along the way realized introducing Adam as Vision would save the studio alot of trouble. When you really dissect it, its quite brilliant how all he had to do was replace the Enclave/High Evolutionary with Dr. Cho and her tissue-building "Cradle" (a great substitute for the cocoon) to bring Adam into the MCU.
From this point on movie Adam can fully become comics Adam. That moment when he "clothed" himself after seeing his reflection, and then made himself a cape after seeing Thor's...seeds that can facilitate a visual evolution over the course of the next few movies. He can just
choose to give himself hair and a skin color closer to ours. Same goes with the name. He currently doesn't have one. He can adopt it himself (appropriately) or they can have someone name him Adam, perhaps Wanda.