Well you've only disconnected one of the 3 pickups, there is also one in each of the front wheel arches. My guess is that it's in limbo & will eventually tell you that they're missing.
Troy, sounds to me like one of your sensors might have died - like you suspected. But you'd have to check it on the scan tool to back that up.
I've thought a lot about what's involved in tricking the system.. its pretty smart!
I think the best way of shutting it off would be for someone to develope a flash for the fcm, to alter the vehicle configuration; telling it that the vehicle is not equipped with the TPMS.
Alternatively, you could design a transponder that duplicates a viable output signal of pressure & temparature.. & just locate one inside each of the wheel arches.
But at the end of the day, having the TPMS is a good thing. Just need to have a bigger variety of wheels that allow correct fitment of the original sensors
My 2cents!
Cheers
Phil