Well, it's not just that - Blizzard is actively selling the non-remastered original versions (running on DOSBox exactly like the GoG ones) directly from the Battle.net launcher now too. They've essentially in-housed the exact same product that they originally commissioned for GoG.
It may or may not be a jerk move, business-wise (I have no idea what their original agreement with GoG was when they launched it there), but from a purely preservationist point of view, nothing has yet been lost as a result of this.
(And while it's tempting to say that in the long run GoG would have been better stewards of the old builds than Blizzard, and that would certainly be true for 99% of publishers out there, keep in mind that Blizzard has successfully kept up servers and downloads for games going back to the mid-90s up to the present day. Blizzard takes preservation much more seriously than almost anyone else.)
They've released a Warcraft Battle Chest which includes remasters of those games at three times the price (but also includes Warcraft 3), hoping to capture those old game sales into a more expensive offering. Awful for consumers to not just have both options, but shareholders > consumers for public companies unfortunately.
