Keep your fingers crossed that DP doesn't carry that over to the combined airline. Frankly, US' preferred/choice/standard coach never made sense to me since they're all the same seats except for where they're located in the cabin.

The work-around for US elites is to wait for the upgrade windows to start opening and grab either a preferred or exit row seat when they open up because the previous occupant got upgraded (assuming the elite doesn't get upgraded). Not sure how, or even if, that would work for you booking a day or two prior to departure.

Jim