In this case I would recommend to contact the manufacturer of the fan in order to obtain the MTBF, Intel does not have that information since this is fabricated by a third.
i check the label again and there are more information:
but although with this information i found nothing at the web.
i think intel have the technical datasheet of theier own fans/cooler.
at nidec is no information about an intel cooler.
I would recommend to contact them via phone or email. Like mentioned before Intel does not have that type of information since we do not fabricate fans.