Huge mess - I've posted on the Amex forum about this. As platinum card member, I relied on the Preferred Select membership for upgrades. Avis blindsided Amex with the First program and now Amex platinum has no benefits regarding Avis. I was on a conference call with both Amex platinum and Avis supervisors at the same time and it was clear that no one at Amex knew what was happening with Avis.
I was very unhappy with Amex, but now I see it as Avis' fault.
If something isn't corrected, I will stop using Avis.