I've been a programmer since the 1970s. This bullshit theory gets trotted out every few years. 50 years in, and there are more and more programmers, not less and less.
Deluxe! Remember back about 1995, when Windows NT would make programmers 5 to 10 times more productive, and CEOs could get rid of the corresponding head count?
If it is not true (likely), he is just trying to sell the new AWS AI products.
If the AWS AI is so good, they can dogfood it and show the world how they have used it to replace AWS developers.