It's an electrostatic motor, so expect peak performance at close to 0 RPM. It probably won't work well at 1k RPM, but whether "too high frequency" for it is closer to 10 RPM or 100 RPM isn't clear.
There's a video with some waves in unlabeled axis. I didn't watch it.
Anyway, it's almost certainly not aimed at aircraft propulsion or power generation. You may want something like it for robotics, but last time a paper from them circulated around here, they seemed to be focusing on instrument actuators and chip fabrication.
Their applications pages mentions wind turbines and automotive applications and promises increased efficiency vs conventional motors. That would require maintaining 90%+ efficiency at well over 1k RPM. But no specs anywhere, so hard to tell whether this is real.
TBH, I didn't think about low rotational speed wind turbines. Yeah, it may be a big thing for those.
"Electric drivetrains" can mean anything from an excavator moving at 5km/h with 3m large wheels in a frequency of less then 0.2Hz up to extreme race RC vehicles, at 100km/h with 5cm wheels at ~100Hz. A car wheels go barely over 1k RPM, but I don't really expect them to do anything useful for those.
automotive application can mean as well use as windshield or wipers motors
I don't think it was really for automotive applications. It said something like "low speed vehicles". Made me think of something like golf carts or maybe ATVs. Of course without a gearbox, the biggest factor would be what wheel diameters are used since that would be the main ratio with revs per mile.
1k RPM for wind turbines? Is that the usual gearing ratio? Is there any reason to maintain that gearing for a different rupe of motor? From my observation of wind farms, the blades spin well under 1 Hz (<60 RPM)