KetobaK: Guys, good news, as GOG Support said, they have fixed the game and now you can access the pre order bonus content without any problems!!! Thanks to GOG Support Staff that help me with this and for their amazing work!!! DRM FREE FOREVER!!!!
It's solved!!! Hey, can you post that the problem is solved? I can't mark my own answer as a solution :P
Time4Tea: Did they announce this? If true, this is good news and a welcome sign that GOG do still care about DRM-free. However, it would be nice to see them applying more pressure to Hello Games and Sloclap and more strongly enforcing the DRM-free promise on their store. I'll add Wasteland 2 to my wishlist (for when my boycott ends).
They don't announced openly, but yes, it's fixed, I test it myself, I reinstalled the game with the latest version of the offline installer (full offline, disconnected interntet) and it works perfectly, all the pre order content is there since the start of the game!!!! Can you post something like "it's solved" so I can close this thread with incredible good news.
*Screen Capture Below* The Hat is new :V
This