The whole point of this, anyway, is that the storyline was not changed -- that everything the Doctor has personally, emotionally gone through over the past seven seasons is still a part of his history. The whole thing was structured to preserve that emotional arc rather than altering it.
In the main, I agree with this. However, the title of the painting, Gallifrey Falls No More would seem to suggest that history had changed because "No More" suggests that it orginally had fallen.
But, agree, and I think it was brilliant, because it totally recast what we and the Doctor thought we knew. Changed the future course of the character and show without changing what we saw in previous seasons.
Mr Awe