I've received three emails about this launch: One each from Findmypast, The 1939 Register, and the British Newspaper Archive.
As a subscriber, Findmypast is offering 25% discount, and "The 1939 Register" is offering 10% to me "as an early subscriber."
Apart from the finer details of currency and discount, all of the emails are exactly the same, but I think this is the gist of the discounts.
I'm a World Annual subscriber, so perhaps for those that subscribe on a different plan, the discounts will differ.