The file size is also a big hint that it's fake.
Release groups always release RAW (1:1) image of the media they dump. The RAW size of Wii U singled layer disc is around 23GB.
The current nfo states that the dump (ISO?) is 8~9GB.
Even if the dump was scrubbed (assuming they understood how to do it), what would be the point in doing so? Download/store size?
There's no purpose in altering a dump without knowing if doing so won't render it useless for the (future) intended use (piracy).
Another thing is that scrubbing could even work differently on WiiU than it worked on the Wii.
There may be protections preventing modifications.
For example, a scrubbed dump could require to be re-encrypted using the master key if the dummy areas are now part of the encryption/signing process.
There's only one dump available for the moment to compare with a Wii Disc format.
Don't trust release group with dumps smaller than 23GB.
