Pretty much. They're used more in larger airframes.
Because of the size, the airframe itself can create shadows in the antenna pattern, and genrally they're not flown close-in like the smaller or medium sized airframes, so range starts to become more of an issue.
A second receive path out of the airframe's shadow and with a different orentation will extend the reliable range of the model.
Now something new that's starting . . . the satilite itself is a complete receiver, lacking only the output hardware. Some of the control boards (like the KK2) can use the satilite's data output directly and not require a full RX -- a nice cost savings.