I had similar situations with them in the past. From my experience only if there a major schedule (several hours of e.g. different day of departure) you can ask to be rebooked or request an electronic voucher (Mexican airlines generally don't do cash refunds). Same situation with Volaris and Aeromexico. I would recommend not to book with either of them too far out as a schedule change is almost guaranteed. They sell flights that do not have confirmed slot times, hence the major schedule changes that occur frequently.