Please review the rules that you accepted this morning. It clearly states that linking of external guides are not allowed. It also said cross-posting multiple times isn't accepted. The reason your posts weren't showing up was due to the link you tried to supply, your posts were auto-moderated.
We have a guide to mod the "Wii Mode" side of a "Wii U" (also known as "vWii" or "Virtual Wii").
A link to that guide exists in my signature.
As far as I recall, no Wii U update has messed with the vWii side of the system since it launched. So no update has blocked someone from modding it and no updated has removed a previously installed mod.
For more information, ask questions in the guide's thread after reading it a few times.