I believe this is a direct response to the man who tried to walk into Magic Kingdom with a concealed guy but ran away and/or another specific threat.
I am of two minds. One, most security like this is "theater", where just enough is done to appear to be secure but not enough to actual challenge someone with a bomb or gun (hey what if the person just used it right at the security line, for example?)
Second, the amount of hypocrisy going on right now is astounding. Not necessarily on these boards, but online many are saying "I'm happy Disney is protecting us", but slogging other theme parks who use scanners/metal detectors full or part time. Nothing of actual substance Disney can do can be bad or wrong.