Nobody ever accused the ACLU of being smart. If they are anything, they are consistent. And their consistency will spell their doom. I predict they will take this up. They simply cannot let it stand.
This is a bit like the Taxman case about a teacher layoff that was based on race. When Taxman appealed to the USSC, the ACLU, the school system and the race baiters payed her off so the case became moot.
In this instance, there is no one to pay off.
I think the ACLU will let it stand. Evolution is not a big enough hill to die on. It does not go to the core of their purpose. It's a nice fund raising vehicle, but an appeal would dry up future funds from those who lok at evolution as thier one issue.