I think I wrote this already a few years ago, but I toyed with the idea of emailing Gabe (assuming his email still works) with, if nothing else, putting up Half-Life on GOG for April Fools. (Maybe a HL3 would be even better)
I think that CDP could in theory strike a deal with Valve to bring a few of their classics here, but CDP would need a really good bargaining chip.
if CDPR decided to make Cyberpunk exclusive to GOG. Would it drive a ton of customers to GOG, or just lose a ton of money and put the developer out of business because NO STEAM NO BUY?
This would be utter financial suicide. Not because anyone is loyal to Steam out of principle. It's just where most people have their gaming collections, friends, etc. Nobody would organize a boycott, nobody would try to do anything harmful on purpose, it's just that most would simply pass it by. In our current era, when there is A LOT of choice for quality games and most people don't have the time to play them all, being on the first page of the biggest store is really the only meaningful way of breaking even.
GOG is great, all of us on this forum probably do most of our gaming shopping here, but at the same time it's still a pretty obscure and unknown (to the general public) venue. Plus the aforementioned Steam collections and connections.
I wouldn't say suicide
because CDPR has made enough of a name for themselves with TW3 and 2077 is so hyped that even having it be GOG exclusive I think enough people would bite the bullet and get it here. There'd certainly be a financial loss of course but CDP might consider it worth it in the long-term (ie, having millions of new potential customers). EA was able to survive moving exclusively to Origin (granted they have a LOT more content than CDP)
But from a PR standpoint it might be best to take the route of "we want players to have choice - Steam, GOG, console..."
I assume GOG codes will be included in the physical boxes, like with TW3, and that'll send more new folks our way.