There are no limits to perfection)
New contest could be a new start for people who were late. And there no more symbolism with 10th January, cause it was supposed to be a month from the game launch.
Prolonging of contest = more submissions)
Of course there is always the oppurtunity to start a 2nd contest, this did not came up to my mind at first.
However, even tho it is a contest which was orginally planned to end 10.01, still they could have chosen to have no contest at all and they can change the rules however they desire, since they are the contest owner.
You may prolong a contest and you may get more submissions along the way, but sometimes other stuff is more important.
Fixing a game takes longer and more know-how than rating pictures, since anyone can do that.