So I did a little more digging today and I think I understand what is going on here. I commented out the @Model annotation and my code started working as expected. In my description above I neglected to document provide relevant implementation details. This code is exercised in an asynchronous thread kicked off a call utilizing the new concurrent utilities API. Thus there is no active request scope when B.clearCachedModel(Long) is called.
Assuming that my understanding is now correct should I not expect some type of exception to be generated in this scenario?