This seems crazy to me. I am a PM and I am busier than ever. People are waking up to the idea that code is cheap and things can change faster now, so deciding _what_ to make and prioritise in the deluge of ideas coming to prod is becoming completely essential.
One thing LLMs don't have is taste. That's on me.
I think that all PMs will need to get onto the engineering, design, or research ladder. We are already seeing companies eliminate the function here and there and I expect the trend to continue.