The link you're quoting, the one posted, is a second hand US report.

The primary company link is from a UK subsidiary of Mercedes-Benz and is (almost) fully metric (the fundemental units US weights are officially defined with respect to (for more than a century now)).

See: https://yasa.com/news/yasa-smashes-own-unofficial-power-dens...

  Earlier in the summer YASA achieved 550kW (738bhp) from a 13.1kg version of its new axial flux prototype motor, equating to an unofficial power density world record of 42kW/kg

  Now latest testing of an even lighter 12.7kg version on a more powerful dynamometer has shattered this record, with a staggering 750kW (>1000bhp) short-term peak rating, resulting in a new unofficial power density record of 59kW/kg

Just those pesky trad bhp units left hanging like a chad in a Florida election . . .