No no, I get it. What I don't see - and what would be the most important thing to justify a lawsuit - is why preventing a permanent, better representation selection system isn't a greater impediment to voting rights than temporary confusion.
The justification for the lawsuit here is basically, "Evidence - real evidence! - shows certain people are confused when we fix the broken system, so let's ditch the fix and keep that system." You're focusing on the "evidence" part of that, when the logic itself is what's more seriously flawed.
There are so many less restrictive, less regressive options. Educate those communities. Clarify on the ballot in big large-type bold, simple language what they're supposed to do. Even before filing a lawsuit, they should have looked into publicly available information to see whether that confusion actually resulted in electoral result defects. Right now all we have is that those communities undervote. That's a very thin basis for such extreme action here.