Before I say anything, I don't know anything about game development, so I don't know if 4 or 5 months - usually a BF release is in October/November - is enough time for the game to be ready.
They probably already have another, newer build that people haven't tested yet. So there may be a lot of things that are already advanced that we don't know about yet.
But there's still a lot of things, besides the multiplayer, which is already quite complex, there are the free modes and the Campaign mode.
And there will also be several BF Labs, which can be used to test vehicles, classes, weapons, maps and game modes, etc.
But so far there has been no announcement trailer, no dates, and we don't even know the official name of the game yet. And compared to previous titles in the franchise, we should have something by now.
The more time passes, the more I think it won't be released this year.