It IS true for the prototype. Siemens is really good at grabbing these orders for production aircraft and getting their name in press releases, but the actual motor used for the prototype according to the FAA (who I don’t recommend lying to) is the EMRAX one.
EDIT: And EMRAX motors have shown up on lots of other electric aircraft. My day job is making novel electric motors, and their motors are incredibly tough to beat. I have much respect.
https://emrax.com/products/emrax-268/
Up to 98% efficiency. Up to 10kW/kg. Pretty impressive motor, and few electric motor makers like to compare their motors to this high of a standard.