One thing that may have transpired is that from the 60's (and before) to today we have become aware that sodium is potentially bad for us. But this arguement as a reason for curtailing its addition makes little sense. The RDA for sodium chloride is 2,300 mg, or 2.3 grams per day, and even on a sodium restricted diet one is never advised to go below 1,500 mg per day. You can die if you take in less than 1,200 mg per day.
If one adds 2.3 grams of salt to 30 liters of beer, then the entire 30 liters would need to be consumed within a single day just to meet the normal daily recommended intake of salt.