ED Original gamers have to basically BUY Flames of Vengeance expansion to get the DKS Upgrade Patch
A conversion patch would still involve additional costs in time and resources (testing, distribution, etc) over and above that for the add-on, with no additional income. While providing that option would certainly be a good thing, the costs vs benefits still have to be justified.
Hell, a ED Original -> ED Remastered upgrade isn't even being sold as DLC, for those who have no interest in FOV.
Those who have no interest in FoV also do not care that opponent placement and chest contents have been adjusted in DKS, or the flying fortresses redesigned, and will be fine with the upcoming D2:ED patch without any remastered content.
ED Original owners have to buy FOV or just flat-out buy DKS (ED Remastered + FOV) to complete the DKS - or they are out of luck.
That sounds like pretty much every other add-on released, where there was also a gold (etc) combined edition of the game and add-on.
