So does the company decide the nonrev rules or is this something the union(s) can push for? Im familiar with the AA system and it does have its advantages over said massive family hired before any of us were born. There are times its not possible to check in 24 hours prior but usualy if you have a minute to use your phone or have a friend do it for you its resolved. Even checking in late inside 24 hours is still protecting you from many last minute bookings and if you get rolled to the next flight you are now higher on the list. With AAs system you rank high at the top on any later flights if you dont get onboard the first one

Edit: also if plans change like the hub-london vs hub-paris example any agent can just switch your flight while maintaining the check in time