What exactly is your complaint? It seems that it is lack of notification, understandably. Your friends have been accommodated, new routing issued, however it is a shorter layover/connection upon arrival into the US. Are your friends happy with the result, are they arriving earlier to their destination? Yes, No? They can easily complaint to AA regarding lack of notification and they will probably get some miles for the inconvenience. However, if they are not regular AA flyers, those miles will be useless as it will probably sit around on their account, if they have an AA account, unused. They have the option to get a routing that suits their needs. Typically in situations like this, I will first check for a better routing before contacting the carrier and then I will give it to them, instead of them looking for one.

They have the option of canceling the flight and getting a refund, miles will be the most common compensation, but for that, they need to complaint directly to AA. Upgrade, really? what about an upgrade for all the coach passengers that where on the same flight as your friends and where as inconvenienced as well? Seriously, there are not enough business/first class seat available to accommodate all of them.

I've had numerous issues like this in the past, what I've noticed is that AA will send notifications closer to flight date, rather than 2, 3, etc months before. This is why as I mentioned on my previous post, I check my reservations. I also use awardwallet as well to monitor my trips and I receive notifications as well when a flight change occurs. The early I act on it, the better the results are.