in fact transform axis is different according files, and import parameters (left handed, flipwinding order)... because it's a post transformation of bones and it depends of its original matrices...
Blender export inverse y and z and polarity, it's why axis where inversed in wz. But in most of other files y and z are common to wz4, axis are in good order.
I swith back y/z axis it's more natural for most of files.
For blender maybe there is an option to switch axis at export ?