Same as other users reported, I called AA Cust Service 800.433.7300. Told them I was Delta Diamond, and wanted to bring my 20k in business to AA. The gentleman answering the phone said they were matching Delta Diamond. He sent me an email and I had to send in a screenshot of my Delta activity for last year plus a copy of my Diamond card (both of which I was able to pull off Delta.com
I was contacted the next day with a match to Exec Platinum for 3 months, starting within next 10 business days (I could choose).
I can keep for rest of year by achieving:
$4k spend and 35k EQMs.