Update on the 3x points on Amex PRG internet (and some other) purchases: It's still happening!
I just received my monthly MR statement, and the news is pretty much as expected. I received 3x again from Hertz, Amazon Marketplace and Costco membership renewal. Both the Amazon and Costco purchases were listed as Internet Purchase, and Hertz as Vehicle Rental.
Checking my current Amex PRG statement, I estimated my pending points to within 0.5% assuming 3x points on Internet Purchases and Vehicle Rental. I still haven't been able to check whether other Travel spend gets the bonus.