Long-Term Update 1: 2007 GMC Yukon SLT
The service light flicked on in the Yukon indicating it was due for its first service. One MT staffer had mentioned possible erratic behavior from the tire-pressure-monitoring system, so we checked the logbook for notes.
Turns out this individual may not understand that cold pressures vary from hot by one to two degrees and that you'll see a one-degree difference for every 10-degree change in ambient temp.
So the bottom line is that nothing was wrong with our system. This should remind everyone to check your tire pressures regularly, more so during seasonal temperature fluctuations.