It's not selective, the OTA database doesn't have any station with a Tribune ID higher than 65535 (0xffff). You can see them in one of the Notes columns on the transponder maps. The few "additions" we got were just cases of Tribune reactivating the same ID they used for a station that previously had a subchannel. i.e. a bunch of Sinclair stations dropped The Cool TV a few years ago and didn't replace it with anything so Tribune made that ID inactive, fast forward to a few months ago, many of those stations added Grit so Tribune reactivated that ID and they appeared in the database.