AA has a long history of being terrible at marketing its strengths.
When you have so few, it's hard to find them...
I will say, the the A320/319 don't have the new bins and it's a cluster at the end of boarding, coupled with the hard bulkheads, to get bags in sometimes. I don't expect GA's to know all the planes and what not, but the majority of the fleet is 737/A321.