Melissa O'Neill's response back: http://www.pcg-random.org/posts/on-vignas-pcg-critique.html

Interesting read, thanks! The deflection about xoshiro is not particularly convincing, though. It's much more likely that you'll want to multiply your random stream by a multiple of 57 than you'll want to xor it with a 43-bit-shifted version of itself. He also doesn't appear to counter the complaint about the generator getting stuck around 0: http://www.pcg-random.org/posts/xoshiro-repeat-flaws.html

The other parts of the post definitely concern me about using the PCG's described, though. Also, it's interesting to see how PCG can be predicted. I would not have known how to attack it.