1/2 tsp of salt is on average 1,150 mg of sodium. So 4,000 mg? About 1 3/4 tsp of it. That is a LOT!
An average healthy adult needs no more than 2,400 mg of it per day.
So yes, as you can see....even a half bag of freeze dried food is scary! And who eats 1/2 a bag? Few!
You want scary...start looking at menus when eating out if you are in an area that requires it (like King County does). Sodium is more abused than fat these days.
As for me...due to being on a lower sodium diet at home I tell my readers to add salt as desired (unless it is a baked item done at home - baking does need a certain amount of salt to work in many cases.) Also why I call for low sodium bouillon - you can always add salt, you can't take it out!
As for commercial meals there are a few that are of decent levels. Mary Jane's tend to be on the good side (but not all, so read). A few veg friendly entrees by BP are better. But usually if you want to eat a decent sodium diet...you have to make it from scratch.