I assume you have a legal copy of the game?? ...if so...
When you installed the Game Update Data on the Wii U console is made permanent changes to your console ...you cannot completely uninstall it, you can only delete the Game Update Data...like if you are low on disk space etc
Basically if you ever wanted to play the game again, you need to downloaded the Game Update Data from the Internet in order to play it.
Otherwise you can no longer play that game on your Wii U console.
Great thinking Nintendo!
Only way the play the game in a older version is to use Loadiine.