BmB, maybe bothering to read the description in the video you linked to would have given you a bit of a clue to the finished state of that shot

An unfinished clip from ESB:Revisited showing the new approach to Cloud City. It still has a lot of work left to be done to it but it gives you a good idea of how the new shot will be like

This video was uploaded ages ago and since then other shots have been posted showing the progress of the colouring.

As for the cloud city matte, the picture you say the shading should be like has the suns position completely different than the one in this shot. That picture has the sun almost directly to the side of the city, which would illuminate only that section and cause that deep grading. As you can see in the video, the sun is almost directly facing the city, so that kind of gradient would not happen