xa_chan: A bad PR decision, I think, as bad as when they fakely announced GOG was closing down.
No, it is a business decision following the example of every other big developer/publisher that are nickle and diming their customers. Unfortunately we are in the minority as you can see from the main GOG store page, the Expansion Pass preorder is selling like hot cakes similar to big game preorders touted on Steam.
Unlike us most people are content to pay first without actually waiting to determine whether the game is really worth it or not, which isn't really a question towards the quality of The Witcher 3 but regarding most AAA games in general.