On what basis are you telling this? I think, it's more "outdated" skills that are worthless, but the interval of time we have to refresh those is getting ridiculously fast....
Meanwhile in practice the opposite happened. You just need bog standard software development experience with an agent focus. You need to know how to set up an agentic CI pipeline, how to set up on demand sandboxes, basically a lot of devops and software development life cycle knowledge and less AI specific knowledge. It's just that AI caused those old things to become ever more important and urgent.
So what the author means by "AI Skills" are skills that relate exclusively to AI and no other domain.
A career moat, probably. And I agree.