After completing the campaign on legendary difficulty, he will offer you both new exotics of which you may choose one. If you complete the campaign on normal difficulty, he will give you a random exotic. And this source seems to be disqualified when it comes to being able to unlock the new ones. Other than that it is legend/master lost sectors as far as I am aware. I have yet to come across a vex elite force on Neomuna to see what that drops.