Looking at the oftentimes misleading seat map, I can see that all the seats in First are taken on tomorrow's AA flight JFK=>MIA, but for the first time that I can recall I have not already been assigned a specific seat for myself and my travelling companion.

Instead, I have received the following message with our reservations, booked a few days ago:

"...Your reservation is confirmed, but you will need to obtain your seat assignment from a gate agent at the airport. Please check in at a Self-Service Check-In machine at the airport and obtain your seat assignment at the gate..."

Speaking with the EXP Desk, I have learned that two seats are usually held for "airport checkin".

Can someone explain exactly what this means?

Should we be worried about being kicked out of First?! Ouch!