The discovery that there's a gulf between what the Boeing engineers (many of whom are pilots) and the FAA previously thought of as runaway trim, uncommanded tri

The discovery that there's a gulf between what the Boeing engineers (many of whom are pilots) and the FAA previously thought of as runaway trim, uncommanded trim movement, and what they now know about this behavior not being recognized, means that many systems risk factors will get reclassified and thusly will have to be redesigned to be more robust. In this case, one of the main modes for the electric trim running away has been shorts in that system's wiring harness, so it now has to be redesigned because Boeing can no longer rely on the pilots recognizing it. I bet speed trim will get a revamp too.