Pretty sure he knows he has a target on his back and is just using the kid as a human shield. He was never seen in public with his kid until after Luigi.
And with every other person I would say this is absurd, but Musk is weird as fuck and seems to consider his kids extensions of himself, so it absolutely tracks.
I've seen this around and I just don't buy it. Like, he thinks someone who will be so skilled and determined that they get past secret service will hesitate because his son is there?