I’m pretty sure most people who have papers in the ACM digital library already have “preprints” in other freely accessible locations, especially for papers written in the last two decades. LLMS have been able to search/find most of my papers for long time now.
The peer review system was broken before AI, so I’m not sure what your point is there.
My ACM papers are published in full on my website. Not preprints. In fact thats the only reason I have a website, just in case someone actually wants to read them.
The copyright agreement (actually copyright assignment/transfer) with ACM has had a carve-out for this case in it for a while, but it has to be a personal website.
The peer review system was broken before AI, so I’m not sure what your point is there.