This is what he said on neogaf (apparently)
"Yes, we will be matching people together according to their skill,It will be factored in far more than it ever was in Reach. Don’t think I’m spilling secrets to say that Reach prioritized matching based on connection speed with skill levels a lower priority to ensure fast matching.
“Because of our more focused playlist offerings (which we’re planning to update more frequently than previous games) our player pool will be much larger per playlist which should provide more consistent matching by skill AND connection speed.”
Note: I didn’t get this info from neogaf i saw it on an article.