Igorq: "pre-order on GOG" after official release makes no sense.
Even if extra content available in pre-order will be not available on GOG I will wait for GOG version and I will buy on GOG. Because of no DRM policy, because of GOG preservation program etc...
I understand if for someone the extra content might be so important that he/she can sacrifice ownership just to have extra mission. For me extra game content is not worth this sacrifice - for me it is much more important to support real ownership and no "you can play as long as we will allow you" sh*t. For this reason - I will buy from GOG.
Exactly same thinking I have. I thought that I will buy game on EPIC since it is cheaper there and considering fact that I buying licence to play not game itself. But when it is anounced to be here in GOG I will wait these few days. In past I bought KCD1 Royal version on DVD but sadly it is connected to Steam and has note with small letters on package that this copy is related to SSA of Steam which in that time I didn't focus what that mean until I recognised that playing game without connection and checks against Steam servers make really anoying experience for single player game.
So later I bought copy on GOG which I can play on any PC without any account and restriction.
In case of Lion Crest quest I saw some advert available sice day 1 so I guess this quest will not be available in day 1 but maybe it will be available for others after DLCs will be out and it will be part of final DLC or maybe available to buy like addon later but not on day 1 like for peole who preorder.