US Airways Dividend Miles - Status when booked, none at time of flight

I searched but didn't find a definitive question in regards to seating in Y.

I will lose my status before my next US flight (I haven't booked it yet).

I suspect I will be able to select preferred seats in coach at the time of purchase, but will I be bumped from the preferred seating before I fly? If I risk being bumped I would rather just choose a non-preferred coach seat when I book in order to at least assure I get an aisle seat.

Thanks