Just confirming that this is true. You can get him around mid-game.
What? Where? I haven't seen a trace of him and I beat the story already.
I honestly forgot the exact location, but I was flying around to uncover all the dark spots on the map and there was a very random platform in the air and a locked chest, I destroyed the lock and obtained Taskmaster.
I'll see if I can find the exact location later.
One of my best friends has a viral video, check it out! http://www.youtube.com/watch?v=ZrasQOojFyo