I don't know if this was already posted, because I know I was not the only one thinking this, but, who all thinks that the bungie day playlist was a test for a custom "maps" playlist? They said there would not be a custom games playlist I know I know, but still you know maps are different than custom games. Just a thought.
I believe it was to show players who disagree with customs a chance to see how fun they are, while still giving back to the community with the armors.
I agree, it was also in a way a huge advertisement for custom maps, even if they won't have a custom map playlist. Since there were at least 170,000 people playing it. Accually it was mainly a Collanade ad, because I got that about two outa three times