I'll answer the question you pose: NO, but I think it's very bad form for chaperones to deliberately (in this case, pay to) upgrade themselves into a different cabin when they're presumably being paid to chaperone the kids (as part of their job) and are also being given an expensive trip. It would be different IMO if these were volunteer parent chaperones or if the chaperones were paying the cost of their trips. The business purpose of the travel was solely to supervise the kids.