Now I'm quite willing to be proved wrong here, but I'd reckon that VAG would not have a clue which cars left the factory with the updated ARBs especially cars built close to the change point, I do realise that there is meant to be a formal POE of any changes and the parts listings usually do list "for chassis up to" and "for chassis from", but in this case I do not think that it was ever that clear. One thing is true though, if any VAG dealer checked your VIN then they would find out which PR-codes were included in the build of that car, and that would include the ARB diameter - but that size is generic for a range of engines and does not answer the question "has it got the old or new type ARB fitted" - and that is correct information that you will need to let you buy in the right ARB bushes.
Even with an F1 active search they usually list all the anti roll bars on ETKA, you have to measure it first (easy to do if you have a few spanners handy, just slip one over). I'm pretty sure even up to 7 chassis at least they were still fitting the old type of arb to new cars. 9 chassis onwards they have changed to the new type of subframe and binned consoles all together.