AMEX already threw cardholders a bone with the wireless/streaming credit; clearly this was meant as a 'retention bonus' in consideration of the loss of value of travel benefits to a large portion of the cardholder base, so I think it's a lot to ask that Uber credits be held for us indefinitely. AMEX Plat has always been a card with a wide array of benefits which are always going to have varying utility to cardholders - the Uber credit and wireless/streaming credits are just more examples of this.