I think a few others got this excuse and a few other varying excuses (planned holiday shutdown etc) from VW Cust Services, VW Exec office and dealers and differing excuses from all 3 prompted most not to believe a word VW was saying.
Good to see some announcement though of VWUK officially telling dealers a realistic lead time of 25 weeks (although with some recent orders getting a BW in Nov/Dec this year who knows whats going on)
Hopefully it is only a weeks delay (what I had in BW39) but some BW39/40 (and I think a BW38) are still being built with little info from VW on exactly what the issue is!!!!
Well I'm BW39 - and still waiting!
Still 'Being Built' apparently
When I call them - they just say its a stage 7 of 8 !
I give up!!!
Time to turn the heat up on your dealership to find out exactly where your car is, from what I remember there are 20 steps involved from start to end and your dealer should have access to this system.
The tracker site for customers is very basic

Were BW39 cars caught up in the hail storms and the rectory clouded June/July?
Looking at the posted PDF it looks like all cars ordered up to BW42 had a 25 week lead time (worst case)
I feel that individual communications to customers affected didn't take place.
They was I see it, any cars damaged in the hail storm had to be rebuilt, the factory closed for a month too in June/July.