Yeah that is maybe the coolest use of phase I've ever heard in a song. It sounds like the microphones were actually being physically moved rather than it being a plugin. First time that thought has ever occurred to me when hearing a phase effect. I'm sure it's been done though. It's something I've always thought about doing but never got around to.
i thought that too, first it sounds mono and far away then it gets "nearer" or bigger, also this moving microphones around in the studio has been a bit of trend the last years for many artists, not sure why .