I phoned and said that I understood that we would no longer have access to AA & US lounges.

The CSR said that this was unfortunately true due to a decision by Amex's partners. Then he volunteered to see whether I was eligible for a promotion.

After which he offered to enroll me for up to $100 in statement credits to reimburse incidentals on AA or US.

Then he read me a long disclosure, the pertinent points of which were:
This was in addition to the $200 Plat incidentals credit.
It was valid from 3/22 (the date the lounge access ends) to 12/1

I happily accepted the offer.

I had never previously used an AA or US lounge.