Different departments and subsidiaries will operate according to different procedures based on the specific threats and requirements, this happens even in already highly regulated and restricted fields for example Lockheed Martin'a Skunk Works and Boeing's Phantom Works operate on a completely different level than their civilian and even military BAU aerospace departments when it comes to operational security and secrecy.
Not every company, and not every department can and has to operate using the same ruleset, departments that are relatively sensitive or can afford to work under stringent rules may do so, departments that can't or don't really need too won't, life isn't binary there's more than 2 ways to skin a cat ;)