I generally agree with the take. At the moment the models and agents aren’t good enough for someone who isn’t trained to build and maintain a production system. So as long as Eng isn’t significantly more bandwidth starved than PM, PM’s writing production code is not a high leverage activity.
The key issue right now is that the models falter in the last mile, and the last mile is where you need the training and experience to make sure the thing that lands is production quality.
At some point in the next few years I believe the roles will merge. I suspect that PMs will be forced to specialize towards a discipline (design, data science, engineering, etc.) while engineers will also start to see more of their responsibilities covering former PM territory. Most engineers will probably become closer to “product engineers”.