Try to check that in mono… hmmm 
Even CLA don’t care all that much about mono compatability these days (do the same test with some Nickelback mixes of his). What happens, you say? Well, have a listen for your self.
All that said, the Pan Law settings have nothing to do with wider/narrower. The Pan Law is a mono only setting/preference, only considering a mono signal when placed and/or moved within the stereo field.
If you have a static pan setting for a mono signal, you will compensate with volume when mixing.
If you have a moving mono signal (ie pan automation) within your mix, you may or may not compansate with volume automation as well.
Again. Nothing to do with stereo signals and/or the stereo mixdown. Nothing to do with wider or narrower.