Exactly how so? If Yellow gets a remaster or even a remake whos to say they won't add new features like they did to OR/AS?
Besides, personally Yellow Version was a good Pokemon game if you are familiar with the Manga. If you never read the manga before then to you it would be just a copy of red and blue but that's not entirely true.
As for the Mega Evolutions, I don't see why that hurts the game what so ever. Despite the region, does it really matter that they made Kalos and Unova Mega Evolutions in OR/AS?