No way that happened. That's not how elementary schools work. Teachers don't ever organize large events like this.
I read the comments in the original article, and there are local people claiming that the principal emailed the parents with that same threat, and also announced it over the PA during school. When this all got the attention of the media, she threw her teachers under the bus.
It doesn't surprise me at all. My mother taught first grade for over 20 years, and there's a reason principals become principals. This was all about making the school, and therefore the principal, look good in front of a camera.