I think the expanded pie argument is probably valid to an extent. If costs go down, demand goes up. Also, I suspect new entrants to the field will start to slow as it won't be as lucrative as it once was. This is exactly what happened after outsourcing threatened wages in the 00's - followed by insanely high compensation in the 10's.
The expanded pie argument only works when there is something that cannot be done - or more cost effectively done - by the machine.
The argument in the article is that that something for SW developers is increasingly going to be to feed the machine with requirements.
I have no idea how this will pan out, but from where I am sitting the ability to converse and understand business users, even if they stay human ones, better than current sw devs do doesn't feel like much of a moat, especially with the machine's evolving io modalities.
