Without looking too hard, here’s an article from 2010, shortly after the launch of Chang’e-2, saying that the probe’s primary objective is to map out the Bay of Rainbows which is where they plan to land Chang’e-3:
[quote]Wu Weiren said Chang’e-2 would take high-resolution photos of the moon’s Bay of Rainbows area, the proposed landing ground for Chang’e-3.
Wu said four to five areas had been chosen for a landing ground for Chang’e-3, but the Bay of Rainbows would be the first choice.[/quote]
This is followed a month later by an article about the reveal of a Bay of Rainbows map from Chang’e-2 in a fancy ceremony. I don’t know if technical details of the mission were publicly released in the way that NASA tends to do that, but the basic information hasn’t been kept secret at all.
LADEE’s equatorial orbit is part of the mission design because Lunar atmosphere should be thickest around the equator. Wikipedia suggests that the design may have been around as early as 2008, but it looks like LADEE suffered some delays, so it’s rather doubtful that either NASA or CNSA would have expected at the time that the two missions would launch just a few months from each other in 2013.
