I guess you're right.It doesn't because IIRC the Wii U disc drive spins in reverse, so you would need to mod your console for backups to load from disc. There are also other copy protection methods too, probably, but I don't know what they would be.
Probably selfwritten CAT-R Discs would work? Dunno about the Encryption and if OurLoader is able to load such discs anyways.
I ordered 50 CAT-R Discs and a CAT-R Writer.