They put it back in for the MP packs. My guess is that Bungie wanted to take a shot at the 'Newb combo'or this was the original Outskirts cutscene but, cut into gameplay and maybe didnt stick to the point as much as bungie wanted it to or was just made to show an alternitave storyline.
It still beats the original. And i have a new found love for ODST's :heart: