Automatically? No. You will probably have to contact AA and use the terms, for best success, requesting "original routing credit" for your "involuntary reroute". They have no way of receiving reports from UA, etc. you flew, for one thing.
link
Originally Posted by
CPRich
2.5K as a Gold, with no action on my part.
I haven't seen my original routing credited though - my first leg showed up but my re-route of the second leg on UA didn't. Doesn't AA credit you for your original routing in the case of re-route/IDB/etc to another carrier? US always did that for me.