Originally Posted by
canadiancow
... But is there any good way to tell if they're going to swap it? ...
Roughly 2 days out when UA starts the process of deciding, until then UA will show the old config.
Although until you are in the air, nothing is sure.
Watching the pattern of present fight will give a hint.
One exception is if UA decides to sell PremPlus, that will lock UA into the newer config
Also, the further out the flight, and as more aircraft get retrofitted, the chances of the older config decreases.