I have the same post 12b37 experience. For me, cruise and a/c have to be on and I have noticed it's much more likely to occur when cruise is set for around 60mph than at 75mph. It may very well be that the a/c cycling on in the right circumstances suggests a downshift is needed but the car quickly changes its mind. That it's more likely to occur when the engine is lower in the power band may support this hypothesis.
One of the pre-12b37 complaints was a reluctance to downshift; maybe Ford tinkered with the downshift logic and this is the outcome. When I took mine in with this complaint, they applied 2 post-12b37 updates. Don't know yet if this solved the problem.