I think he's referring to the CX-5 GT vs other trims. It's typical on many manufacturers to reserve the full sound deadening tech for the top trims (acoustic windshields and side glass, noise canceling speakers, extra sound proofing, etc). He's just saying that on the GT it's much quieter that the old models, but without knowing if the same changes were made on all trims the lower trims could potentially be louder.
Changes are across all models