@andre_faughn . Which Samsung phone do you have?
Yes, Verizon has final say what goes into the firmware on Samsung phones that they sell.
Tmobile and AT&T do the same.
It also could be that Samsung has retired the codes you mentioned and changed the access code for the diagnostic menu, or Verizon disabled them as you suggested. A very good reason why it would be disabled or changed is because Galaxy 2 ,3, 4, and early 5, had a specific order you go through the menu and it would unlock the phone permanently. Obviously, the telecoms aren't happy about this, especially when these phones are sold at a discounted price.
Alternate ROMs may have these codes still.