I checked email for my alternate email account and saw an email from Jan 11 that was titled "A New Year offer for your new AAdvantage membership". It was a Citi offer:
Apply for the Citi® / AAdvantage® Platinum Select® Mastercard® and earn 50,000 American Airlines AAdvantage® bonus miles after making $2,500 in purchases within the first 3 months of account opening.* The annual fee of $99 is waived for the first 12 months.
Buried in the fine print, there was no 24-month language, but there was something that said
* Please See Important Terms and Conditions
.
"Terms and conditions" was a link, that resolved to
https://creditcards.aa.com/platterms/, which has, among other things, 24-month language.
Offer availability
American Airlines AAdvantage® bonus miles are not available if you have had any Citi® / AAdvantage® card (other than an AAdvantage MileUp℠ or CitiBusiness® / AAdvantage® card) opened or closed in the past 24 months.
It was a 9-digit code, similar to the ones in the physical mailer.
So, this is a warning to be sure to read the fine print and
follow all links on emailed mailers. I'm not sure whether this code would actually be subject to the 24 month rule or not, but I'm not planning on risking it (unless there are data points from others about similar emailed offers)
FWIW this account is under 2 weeks old.