My 9 and 12 year old sisters saw Billy last summer as part of the Destination Broadway program and both were mature enough to handle the language. In fact they didn't even notice it....they were so engrossed in the dancing. Parents need to realize what shows they are taking their kids to and discern accordingly. Censorship should not take the place of good parenting.
Did they curse as much in the Chicago production? Because I didn't notice any "adult language" and that's probably something I'd remember.
A woman walked up to me after catching Jersey Boys on tour in Minneapolis and asked "Did they take out the swear words? My husband and I just walked out, I don't know how they can get away with that." Whatever lady, grow a pair. Or whatever.