I haven't flown one, but looking at the specs, the problem with using the current crop of AoA indicators is that they're designed for a different purpose: warning lights v. fine tuning the approach. They're designed to provide a warning approaching the critical angle attack, with the objective of nudging the pilot out of this undesired flight regime. But in Cubs flying ultrashort landings, this is the desired flight regime.
In the warning mindset, being a nuisance is the point, i.e. an idiot light. For Cubs, what is needed is a very accurate instrument, that provides information without interfering with the pilot's view of the landing area and horizon. I suspect that such an instrument would be a lot more expensive to build, install, and calibrate than is what is currently available.