Originally Posted by
Smiley90
The functional difference between a change and a cancel and rebook is that a change doesn't require existing award inventory if you only want to change part of your existing itinerary, a cancel and rebook requires availability for your whole itinerary.
For AA bookings, there's likely always availability at a higher price point, so functionally cancel and rebook is always going to be available and show - it'll just charge you more miles (as is visible on your screenshot).
It's just not really a "change", per se.
I don't really understand what you are saying, but I will take your word for it.
It looks like they still have some bugs to work out. That first one in the screen shot should be an even exchange (and it is if you click on it). +10k is for F. The other two are correct for Y.