The responses they've given you are laughable. I would imagine they either don't know the answer as they're powerless or there have been no confirmed build weeks (which is what I've been categorically told) and they don't want that being widely publicised.
Also they won't be publicly seen commenting on anyone elses orders (trends or otherwise) other than your own.
From my conversation with Lisa at VW twitter I think it is far from easy for them to get this information (yes, this is part of the problem!). How it works is if she has a specific order number she can make enquires about it. Unless you can give her every GTI and GTD order number that have been placed in the UK and then wait for her to check on each one individually she can't answer.
As I pointed out on another thread, VW in Germany *should* have an order tracking system set up so there is a database of each order (which you can filter by GTI/GTD for example) that will inform VW UK of the current status. They should update it at least once every week or two weeks with the latest data. It should feed directly to the VW tracker website.
Now if they had that, and it worked, it would be simple for VW UK customer service reps like Lisa to give us up to date and TRUE information about if cars have build weeks assigned, if not when is estimated they would, and how much change do you get from estimated to confirmed based on historical data. I therefore conclude they either don't have such a set up (system failure) or they don't want to use it to help us out (failure to understand customer service). Anyone think of another explanation?