You would imagine he read it at some point. You would also imagine his CEO would have internalised Paul Graham's most important piece of advice about communication (writing clearly).
I have no inside information on this one, but YC has been around for 18 years, and pg left the president role 9 years ago. It's been about half of YC's life that he's been out of the day-to-day stuff. It's absolutely not obvious that he'd be reading each announcement that goes out (I'd be surprised at such).