I booked a trip connecting through DCA;

Shuttle arriving at :29 past the hour
Next flight leaving on the hour (i.e., a :31 connection).

Surprised that AA let me book it, but it did.

Now it looks like the Shuttle is arriving at the B terminal, and not only is my next flight leaving from the Express gate 35x (requiring a bus to the plane), but the next flight is leaving now at :50 past the hour. So I have 21 minutes to get off the Shuttle, take the insanely slow bus between terminals B and C and take a bus from gate 35x to the plane. If the Shuttle is early, this could work, but I doubt it.

The flights are tomorrow. Will AA let me go ahead and get confirmed seats on other flights (ideally on another routing, connecting in CLT or PHL) without paying $75 for confirmed changes? (I am Platinum.)

Thanks.