AA has two different configurations of the A321: The three-class transcon one (10F/20J/36MCE/36Y) that was introduced first to much media fanfare trumpeting the flatbed seats, and the two-class version (16F/19MCE/129Y), introduced much later and with no press ballyhoo at all. AA doesn't even list the seatmap for the two-class one on aa.com - they only have the transcon variant on there.
Both types are labeled "32b" - a first for AA who otherwise distinguish different configurations with unique names and historically have always done so. AA has three different variants of the 777 flying around - and all three have unique designators (777, 772, 77W). There's two different types of 757 - also with unique names (75L, 757). You know what you get when booking these types.

For the uninitiated, using the '32b' designator for both configurations can definitely be misleading - one may very well think they'll get to fly in that heavily publicized plane with the flatbed seats upfront when they see '32b' popping up while booking, the more so as AA in all their marketing material specifically highlight "Just look for "32B" under plane type when you book" so people got to recognize '32b' as 'the nice plane'.

AA should have given the domestic two-class variant another designator and not also label it '32b'. Hence 'misuse'.