When following Unity's documentation on humanoid configuration (arms, hands and fingers align with X axis in unity) the hand pose in VRChat is incorrect.
In the first image I am physically pointing my finger straight down. The laser pointer is correctly aligned with the controller, the avatar hand is not.
The second image shows the controller wireframe tooltip, further highlighting the extent of the mismatch.
The third and fourth images show the issue occurs across other avatars.
In the fifth image I counter-rotated the hand in the humanoid configuration in unity by roughly the angle mismatch, and while that corrected the angle mismatch, it has introduced a number of other problems (finger rotation axes are now wrong, laser origin is in a strange place) that make it useless as any kind of workaround.
Counter-rotating the fingers to fix their rotation in this case also negates the rotation correction in the first place.
This behaviour is present on both live and IK beta, pictures are from live.