Hello,
I confirm that it works on my WIIU 5.5.2 EUR version with http://u.drg.li/
I clicked on fast version link and then the big exploit link.
Afterwards I installed Haxchi as documented here with New Super Mario Bros (EUR E-shop)...
btw i feel this a good time to remind you guys that sea of thieves was made by rare, who also made DKC1-3 and DK64, alongside banjo kazooie and conker's bad fur day