Yes, unfortunately, Invader Zim got cancelled. Whenever Nickelodeon releases a show that's liked by people other than kids and it's not named Spongebob Squarepants, they cancel it. Other examples include Ren & Stimpy and Rocko's Modern Life, and The Angry Beavers, too, to a certain extent.
As for the soundboard, the sound quality was quite erratic. Many of them were too soft. It's not the best Gir soundboard I've come across on this site. What really made it worth it was the Zim theme song.