The big part that made Yellow cool, Pikachu following behind you, was added into HG/SS. And the extra arch around Suicune and Eugene was a part of HG/SS as well, which was a big part of Crystal the first time around. So, while they did not have their own stand alone remake, the elements that made Yellow and Crystal special did go into the game. I expect a simialr with OR/AS, parts of Emerald will be in them