I am both United Premier 1K and Delta Diamond Medallion Million Miler. I emailed American Airlines Customer Service and they asked me to send proof of status and a summary of my miles and segments for 2016. They then offered me:
Executive Platinum status for 3 months. If I earn 35,000 elite qualifying miles (EQMs) or 40 elite qualifying segments (EQSs) and spend $4,000 elite qualifying dollars (EQDs) in 90 days they will extend Executive Platinum through January 31st 2019 and deposit four (4) one-way Systemwide Upgrades into my account.
on December 8, 2017