At least in my car, it previously had the older type of pump and the separate sensor.
Then it had a crash with the previous owner, the pump was replaced by a newer one, but the sensor remained plugged in.
When I unplugged the sensor, the pump being the newer type, continued to work perfectly. My VIN is in a very early (2000) range: WAUZZZ8ZZ1N0144XX.
If I understand ETKA correctly, then power steering pump 8Z0 423 156D needs the sensor, 8Z0 423 156H and above do not need the sensor. Also, my guess is that the later pumps do not need the sensor, but will be able to use it if plugged in (though I see no need, as in my understanding, even the very first A2 supplies the required information through CANbus).
In short, I do not think it is possible to buy a newer pump and have it not work. It is possible to buy a too old pump / pump not for A2, and have it not work (well, it will work, but in emergency mode, with lower steering assist and no dependence on vehicle speed/angular speed).