Yes. 64 bit python is mandatory, as is stated in section 4 of the release note. This is clearly the reason why you run into that problems: glymur as well as the library for the atmospheric correction are expecting the 64 bit python.
32-bit Python is not compiled LargeAddressAware, meaning it will only be able to address 2GB of user addressable memory space per process thread running on either 32-bit or 64-bit Windows. This is by far to less for the atmospheric correction of the 10 m images.