Increasing the torque density compared to the current state-of-the-art would be a big deal for robotics applications.
Aviation is probably the sweet spot application for this motor because decreased weight means increased payload and money. The increased cost is less of a concern than in, say, your cell phone. If you could run the motor without a gearbox and without active cooling, that would save costs in other areas and also decrease maintenance costs.
The "too good to be true" part of aviation is if it, together with battery technology, is able to keep airplanes in the air for a significant amount of time. The high energy density of aviation fuel means that we can build a "good enough" efficiency jet engine by building it like we do today, and just throw fuel at the problem to keep an airplane in the air. With electric propulsion the energy envelope is much tighter and we basically need these miracle solutions in battery tech, motor tech, or both, to make it viable. The presenter's premise was that an airplane that currently takes 180 horsepower to stay in the air, could do the same work with 90 horsepower if the motor and fan were designed differently. Many people are looking at the battery side of the equation, but not many people are looking at the motor side of the equation and there are significant gains to be had here. He then presents evidence indicating that designing a motor and fan differently is possible, and that current turbofan designs are optimized to work with the constraints of jet engines (ie, needing gearboxes to generate enough torque to run bigger and bigger fans).