What the story doesn't tell you is the child was banned for alcohol after turning the water into wine.
This is nothing more than the Alliance Defense Fund's press release. It doesn't tell you much in the way of details. It's one thing to go as Jesus. It's another to proselytize and disrupt the the festivities of those witches and demons.
I disagree with half of that.
The school can not prohibit the kid from proselytizing (without violating the first amendment). For it to do so would be violating the separation of church and state.
They can stop him from disruption-- but this is another issue altogether.