VW UK have said those spec changes take effect from week 22
Good post :-) Quick question - where did VWUK say that?
Well you know just as well as I do that they never directly said that

The BW22 assumption was made as VW UK announced in the MY16 document that an inflationary price rise was taking place. The same day as the price rise appeared on the website (24th April) that extra spec appeared too. As we know the spec changes have since been retracted
A new price list has still yet to to be published since the current 1st April addition doesn't contain 2016 changes, price rises or any spec enhancements if they are still happening