Wonder if this stops wii mode home brew. Doubt it, but I dunno.
It wouldn't. They would need to issue a Wii firmware update to do that. It's literally a Wii on there. And even if they could patch it, they can't fix the games that have the exploits in them because... guess what! Nintendo can't patch games on the Wii! The Wii does not have the necessary bits and pieces to do that. And since this is literally just a Wii, version 4.3, it still lacks that capability. Nintendo updated nothing about it when they put it on the Wii U before shipping the console.
I believe they don't care about the Wii mode at all. They gave up on blocking homebrew two years ago. They'll start to care, however, when it leads to the Wii U becoming the next victim.