This is kind of a big deal for no one, including AmEx (in any of the literature they sent me), to mention.
How are you defining "no one"? It got a lot of blog coverage, and there's an FT thread:
https://www.flyertalk.com/forum/amer...st-2019-a.html
But I agree with your main point that AMEX is remiss in not mentioning it prominently on the benefits page, and PP also ought to note that not all PP memberships provide restaurant access.
(I did find a notice on a PDF form from AMEX for enrolling in PP but that's rather late to be finding out about it)