Question about vaccines? Why ask a doctor when you can ask a former playboy model? Illuminati? Instead of asking an expert on European history, lets ask a rapper! Orbital dynamics? Instead of checking that book on physics, lets ask the former business manager who hears aliens in her head.

As for these particular lyrics, they are an extremely lame play on a popular phenomenon, all in the hope of getting your attention in a way that translates to $$$ or £££ or €€€ or what have you. I don't know if the writer is contradicting himself. Doesn't look like it, and I don't think it means anything either way. The whole gist of the song is: "It ain't the end of the world / Ohhhhhhhhh / We gonna live like its the end of the World."

In other words, "Obviously, we aren't all going to die per some crackpot conspiracy theory in 2012, but let's party like we're going to anyway."

Not that this artist's opinion one way or the other has any bearing on anything.

The song's title is a reference to the 2012 phenomenon. Of the song, Jay Sean said, "I saw the film … and I started to hear about the actual conspiracy theory and I was like, 'OK, so here we go. It's that whole Y2K thing again. And that didn't happen, clearly." "Sometimes you need to remind people to let go of all the heaviness they're carrying through the day. Yes, you had a stressful day but it ain't the end there. That's why it's called '2012 (It Ain't the End)'. It ain't the end of your day, it ain't the end of the world. It ain't the end of anything. It ain't the end of your relationship. If things are going bad, you can always fix it. That's what the whole point … of this song [is], to just enjoy the moments."

As quoted from MTV

I really am this close¹ to flipping about this nonsense. I cannot comprehend just why you and others are actively searching song lyrics for references to this that and the other. I made a lengthy analogy over in this thread at how easy it is to pick apart any song and create a grand conspiracy.

Because I can make a conspiracy about a nursery rhyme, it doesn't mean the conspiracy exists in the first place.
Because someone can sing about the Illuminati, it doesn't mean they exist in the first place.
Because someone can sing about Jesus Christ, it doesn't mean he existed in the first place.

Is any of that making sense?

It is a song, it represents the singers viewpoint, it concerns the interests of the band, their audiences, their money grabbing producers and what have you. It doesn't represent the world will end, and most importantly it is not proof the world would end. If songs were proof, cows can reach the escape velocity of the Earth, circle the Moon a quarter of a million miles away, and return back safely to the field they leaped from.

Last time I checked, cows had difficulty jumping full stop.