Not that I know of (but not an expert), the rotate tool will work with the animation mode but it rotates the animation path not the object, as far as I know. I only played with one Mixamo (pre-Adobe). I understand from a post by Steve that there are a couple different formats but if it’s like the one I have you can maybe do what you want by grouping the rig parts hierarchy and the mesh hierarchy under a single null and rotate that null (with the Model tool).