The thesis that AI is rewriting the PM role stays abstract until it has a face. The face is usually your best performer on the old scoreboard: the person whose craft is the exact thing AI just made cheap.
Competence was never the problem
On my team it was the strongest document writer I had, whose specs other PMs copied and whose strategy docs survived exec review intact. Her skill was real and it was suddenly abundant, and abundance is what deflates value. She was collateralized in a currency the market was devaluing in real time. The tell was that she worked harder at the deflating skill, because when a smart person feels the floor move, the instinct is to do more of what made them valuable. It is the most human response and exactly the wrong one.
The conversation, and the timing
My failure was softening the message to protect the relationship, which really protected my comfort and cost her two quarters of runway. When I finally said it straight, her first question was why I had not told her sooner, and I did not have a good answer. What worked, eventually, was separating her worth from the deflating craft: the judgment underneath the documents was always the real asset, and clear thinking is the scarce input in the new role too. Then real support, time to learn prototyping, cover to be bad at it, a smaller scope to rebuild an evidence base on the new currency, and honesty about the odds instead of false reassurance.
The hard part of this transition is not the tooling. It is telling your best person the thing they are best at is no longer the thing, in time for them to act, without making them feel disposable. Find that person on your team and have the conversation now, while they still have runway. The cruelty is never the honest conversation. It is the delayed one.