Hmmm, well according to the Support FAQ
"Activation and playing the game will be possible:
- at 00:01 hour at the night between 15th and 16th May for the Collector's Edition
- at 00:01 hour on 17th May for the Premium Edition
- at 09:01 hour on 17th May for the digital editions
If you attempt to run the game before the dates given above the program will close without any warning immediately after entering the Product Activation Code."
If those times are PST then activation for GOG/Steam/D2D version is not until 4PM (16:00) GMT right?