mechmouse: If they don't do it this year then I'm guessing there is some legal arrangement stopping them.
Razor444: I would not say a bunch, but wrong, GOG is not CD Projekt RED?
They are sister companies.
The problem is there are things that happen in the background we mere mortals never see.
VALVe has a near monopoly, and no matter how great of a game W3 is they could not afford to not release on Steam. Which means there could be some kind of contractual restriction stopping CDPR from using GoG connect with W3.
Not saying there is, but there could be.
Other reasons could be not wanting to devalue those that supported GoG in the first place.