Update on my circumstance:
TL;dr - I'm as happy as I can be, barring being able to travel.
AF cancelled the flight (SFO-(CDG)- LIS r/t) yesterday, contacted AMEX directly, and I received a call today from AMEX Platinum Travel offering full refund.
I have to say, I chose AF as my preferred TATL carrier for a number of reasons, but one of these, counter-intuitively, is because of the many times AF has had to deal with service disruptions and, at least ime, has been pretty damn good at it (having had more practice than most any other carrier).
I always use the Amex IAP because it saves me multiples of the cost of the Platinum card every year (obviously, not this year).
I'm very pleased with the performance of both my chosen travel partners.
YMMV, of course.