Got my answers.
To keep everyone updated. SAP supports Microsoft PDW 2012 version in BI 4.1 SP4 onwards.
The support is only available for Single source universes and not for multi-source universe.
Interestingly, SAP PAM does not provide details on whether the support is available only for UNV or UNX.
I am assuming that when they mention about windows 64-bit column in PAM, they mean support for UNX.
@SAP Members: Please help me know whether my understanding is correct.