Arcade.Body copies these from sprite.rotation, but that's incorrect.
They should be copied from sprite.angle, as in Arcade.Body#preUpdate.
This Issue is about
ArcadePhysics Body.rotation now reads its initial value from sprite.a…
…ngle instead of sprite.rotation. The property was immediately replaced with the correct value in Body.preUpdate regardless, but it keeps it consistent (thanks @samme #2708)
It doesn't functionally make any difference, as it's replaced immediately via preUpdate anyway, but you're right, it should use that value instead, so I've fixed it in dev.
I figured as much, but thanks. :)