I think Citi / Mastercard simply expected Visa / Amex to go along with the cuts that led off with Discover.
Suggests that there is still competitive dynamics in the payments sector.
Airlines would have all lockstepped together, following whatever devaluation Delta invents next.
The best way people can impact this - move spending away from citi (especially high interchange transactions like travel) and use retention calls to complain about the benefit cuts.