Just to add some insight
The look back period is controlled by VISA or MASTERCARD
So whatever VISA or MC you have, they set the policy -- does not matter who issued the card.
Amex is different because they do not have the same strict look back period. Older charges were honored.
Regardless, I'd rather get triple points on my Sapphire Reserve for travel as it gets me many free flights and travel insurance. Gave up my Amex Platinum long ago. I do not expect to face another disaster like the one with Crystal going forward.