There definitely seemed to be some sort of specification update in 2015. The critical factor for me was for the sensor to be able to transmit @ 433mhz in order to communicate with the OEM "TPMS Brain" in the car.
Spoke to one of my trusted VW Indepndant Tech's today, and he agreed with my logic. His pricing was similar to my find on eBay, then he would've added a handling markup charge. So...for the sake of about $250.00 I'm gonna give these a go. if they don't work, they'll be 'dead weight' for the next 70 - 80k klms use I get out of these rims and tyres (Pirelli Scorpion ATR 255/55/R19)
You can buy dual channel TPMS sensors that work with both 315 and 433 mhz receivers. These are useful if you're not sure which frequency your car has, or when you have sets of wheels that may be fitted to a stable of Touaregs covering different years.