Ha! I’d bet the security head did not do this of their own accord, there was almost certainly a higher-up approving it. And what would apple do, replace their head of security (who is willing and able to navigate sociopolitical constructs in order to do their job to the fullest extent possible) with some random fellow who would turn around at the first “no” from some beurocrat and report back to senior leadership that the only people who will be allowed to have guns on Apple campus are the criminals? Highly highly doubtful.

If they do get fired, it will be as a scapegoat, probably with a large severance, and any company in the world would hire them up immediately.