Music of the Spheres and "The New Age" Spoilers
Both deal with Mi-go and Ghroth, but in the former scenario, just having Ghroth's signal being picked up by a radio station causes mass insanity in the town, and the Mi-Go are trying to stop the signal from being picked up. But in "The New Age" Ghroth is brought into the solar system with no real effect... No Great Old Ones awakening, no mass insanity, and the Mi-Go are the ones who bring him into the Solar System.
Now, given that the Mi-Go are meant to be studying Humanity and mining earth, and are trying to do so before the Great Old Ones awake... bringing an entity who is meant to wake up Great Old Ones near to earth is kind of... well, shooting themselves in the foot. Hmm... I may not be making myself clear here...
Okay, Mi-Go study Humanity and Mine Earth. Seek to prevent/slow down Great Old Ones awakening.
Ghroth causes insanity on a mass scale, and wakes up Great Old Ones.
Why would the Mi-Go bring him to the Solar System?
(Personally I "fixed" it by switching the bad guys behind "The New Age" to the K-n'yani, who actually want to wake the GOOs)