Unity's fbx import will convert it, but have non zero values in the rotation fields, with no way to set the default rotation to identity (0,0,0).
Especially when writing scripts to instantiate objects
I'll have to agree on that. Was thinking from a manual import POV. However I remember you can get a 0,0,0 rotation if you pre-rotate the object/ pivot in 3DS Max before exporting. Will have to check this out again as my memory is not to be trusted.