I believe the original idea was that the land would open around the time of the 2 Avatar sequels being released. I'm not sure what the timing of those sequels or the land opening are looking like these days.
So further expand......
The area clockwise between the Oasis (park entrance) and Africa was originally intended and prepped for the construction of the Beastly Kingdom section of Animal Kingdom (The reason for the Dragon on the AK logo, and the 'Unicorn' parking lot section). When the AK budget was cut, Beastly Kingdom was not built, leaving that section of land empty.
At some point, they realized that there was not anyplace in the park for Meet and Greets, so Camp MM was quickly and cheaply constructed on the plot cleared for the Beastly Kingdom (and in actuality... only about 1/2 of the prepared land space) in order to provide for the park's need for meet and greet locations, and to provide more space and things for guests to do. FotLK was hastily put together as another entertainment option for the guests utilizing existing parade floats no longer needed for parade duty and put into the area.
Camp MM was always intended as a temporary placeholder until they completed the Beastly Kingdom land a few years later once the money was available. Unfortunately, Beastly Kingdom was not to be, and like Disney's many other "temporary" structures (Mickey's BirthdayLand, The EPCOT Wand, the MGM BAH, etc), the Meet and Greets and FotLK remained in place for years.
As an aside... There is still at least 1 set piece that was built that showcased Beastly Kingdom's inteded location within the park. While it's much harder to see now because of the plant growth and elimination of the old River Cruises, It can still be seen if you know what you are looking at over the side of the bridge heading into Camp MM.
There is a small little rock outcropping with a little waterfall next to the bridge on the Camp MM side. The outcropping is in the shape of a dragon's head with the waterfall originating from it's mouth.