Over on their Facebook page, Flightbeam teased a picture showcasing 3 of their upcoming airports.
Out of the 3 sceneries shown, 2 have been confirmed thus far: KPDX Portland at the top and NZWN Wellington at the bottom. However, the scenery in the middle remains a mystery. Guesses in the comments of the post are all over the place, with a few guessing SEQM Quito.
Through images I found through a quick Google search on Quito, my (personal and unconfirmed guess) is that the mystery airport is indeed Quito. This is just a guess at this point, but the images I was able to find are rather similar to the teaser shown by Flightbeam. We expect to know for certain as the scenery progresses closer to a release.
You can find the images I based my guess on below. Notice the distinct jetbridge architecture, the terminal roof, and the various ground vehicles scattered around.