At one time I played around with the cooking theory of seasoning before the SV, vs cooking with no seasonings at all, then add them at the sear, vs the third option, of add all seasonings except salt before the SV,
Kind of depended on what I was cooking, but the seasonings in the bag seemed to impart more flavor from the spices into the meat. Salt in the bag or no salt in the bag was a fine line, can't say I remember much difference.
Sometimes there is no way around it, like if I put soy sauce in the bag. Some things I don't sear, so I feel that salt is necessary in the bag.
The only compelling reason I could find to season but not salt before the SV, it's that if it's being seared and I'm dumping more spices on at that point, and this will include salt for the crusting, I don't want to over-salt the meat.
Cooking with no seasoning until the sear was just bland unless I put a really heavy crust of spices on the meat.