I don't believe that this delay is so they have a couple more weeks to work on the game at all. I'm pretty positive that disks have already been printed if they were supposed to release in two weeks. I would bet that they worked out a deal with Microsoft so they could continue to make people think this is an Xbox One only game. I'm sure it was the reason many people upgraded to the Xbox One and they probably want to keep that going.
These days just about every game comes with a giant day one patch along with several more patches in the next few weeks. Multiplayer issues haven't seemed to stop publishers from putting games out on the shelf before, especially EA with their Battlefield issues. We are in the get it out now and patch it later era and everyone already knew this wouldn't be the best version of the game.
Unless it's broken to the point where it's unplayable I don't believe their story for why the game is delayed 2 more weeks. If the game truly is that broken I don't believe that they can fix it in two weeks.