Naaa, everything will be fine, and here's why:
- The eShop on the Wii U may close, but as long as you're logged into you're NNID online you'll be able to purchase games from the Nintendo's website, then download it via the purchased part of the actual Wii U eShop. In case you didn't know, you just can't buy games from the Wii U eShop, not download already purchased games. You can also still use You can find Nintendo's official statement about it (but for Japan) here
- And even if I'm wrong about that, it doesn't even matter! Something called Tiramisu exists, and it's basically CBHC (or Haxchi if you don't want autoboot) but instead of needing a DSVC title, all you'll need is the health and safety app (which every Wii U comes with). Plus it's kind of better in most regards and will still be updated by its creator, so I'd say it;'s a win-win! If you want to learn how to install Tiramisu, then you can go here.
And yeah, that's why I personally wouldn't worry too much about it