American Express is now reporting new credit cards to credit bureaus much sooner than before. Previously new American Express cards would be reported to credit bureaus after the second statement cycle. Originally it looked like the new rule as that these would be reported after the first statement cycle, but there are datapoints of the cards being reported mid cycle (as soon as 12 days after opening. Datapoint sent in via e-mail) as well. It’s probably best to just assume that these accounts are being reported immediately for now. The reason this matters is for Chase 5/24 purposes.
Hat tip to tehflip449 & Reader Vic