A town stupid enough to pass that act is probably dumb enough to go bankrupt defending it.
But the bankruptcy thing is no different than what Industrial companies, and Walmarts do to towns all over america. They have the deeper pockets for litigation.
The ACLU is probably sponsoring the lawsuit, but usually their are multiple plaintiffs and aggrieved parties to the suit. They are picking the ones that have what they believe, clear constitutional grounds to be overturned.
Now if Hazleton passed their law - it is likely that 20 other municipalities have passed something like it, because that is usually what town boards do. Though it is likely that somebody other than the mayor of Hazleton wrote this law - if it is dumb and unconstitutional - they are dumb asses twice over for passing the thing over the advice of their city attorney.