I'm inclined to believe it. I don't care for his music, but he's really impressive from a technical perspective. He can zero in on incredibly tiny pitch variations, when listening and singing. Hearing him sing microtonal stuff is downright intimidating.
Anyway, since he does have absolute pitch, I think he is very strong evidence that it doesn't limit you to A=440 and 12 tone equal temperament, because he is frequently wildly divergent from that, exploring microtonal music, harmonic series tunings, etc. It seems to be freeing rather than limiting (I understand some of that stuff on a theoretical level, but not on a level where I could improvise or compose in those languages without a lot of work and a whole new approach to ear training...musical concepts he studies and seems to grok in days or weeks would take me months or years).
Anyway, since he does have absolute pitch, I think he is very strong evidence that it doesn't limit you to A=440 and 12 tone equal temperament, because he is frequently wildly divergent from that, exploring microtonal music, harmonic series tunings, etc. It seems to be freeing rather than limiting (I understand some of that stuff on a theoretical level, but not on a level where I could improvise or compose in those languages without a lot of work and a whole new approach to ear training...musical concepts he studies and seems to grok in days or weeks would take me months or years).