Both had vacancies on the last AE, so they can be offered in virtually every class (fewer 765 vacancies total up for bid). The appearance or non appearance of a specific base and seat has more to do with forecast/expected training resources, and so it's impossible to make accurate, generalized predictions on what positions will or won't be offered to a specific class. Do. your best to understand the pros and cons of the available positions and bid what you think you want.