The tire pressure warning light is there for a valid reason--period. If everything is working lie it should, it should not be on--period.
Now, if the temperatures have changed from what they were when the tires were initially inflated, that can trigger it as tire pressure drops when ambient temps drop. If everything was initially fine and then it came on, that can be the reason, if the pressures go "out of programmed parameters", so to speak.
I presume that it is a direct reading system as GM uses rather than using the wheel speed sensors to note a wheel turning faster than its axle-mate on the other side of the vehicle.
It is possible that the system has not "learned" where the individual sensors are on the vehicle, too, so it could be that the pre-delivery inspection operatives might not have done that when they had the vehicle. I do know that if the tires are rotated, the system must relearn where the individual sensors are on the vehicle so that correct readings can be transmitted to the system. Each sensor has a unique radio frequency code th the system detects so it knows where each tire/wheel is on the vehicle.
If the tire pressure light is on, you should be able to read each individual tire's current pressure via the Driver Information Center prompts. OR any other time you might desire. Either with one tire's pressure per prompt or with axle pairs.
The light can also be tripped if the tires are inflated too much. I also suspect that you can program the "relearn position" function that way too, rather than having to use a scan tool.
There might also be some information on the system in the owner's manual.
OR you can play the "dissatisfied customer" and take it back to your salesperson and request he/she get it taken care of BEFORE you get your Delivery Customer Satisfaction Survey.
Check the Driver Information Center FIRST, to see what the tire pressure readings are. If you desire, then you can cross check that with a tire gauge of known accuracy to see how things are . . . ONLY when the tires are "cold" rather than after driving.
Regards,
C-BODY