Disney did this young lady no good by rehiring her. She will think her actions were justified. She will be in for a big surprise when she tries something at her first real job and gets fired. What she was asked to do was allow higher ups to make PR decisions rather than letting the low level employees decide what details to give to the public. This happens every day in businesses.
I am in HR and I have dealt with young people who act so over the top about perceived injustices. One quit because we could not close two hours early on the Friday before a holiday. She went around to say goodbye to the other employees (small office of 15) and started to tell each one about how unscrupulous we are and such an unprofessional employer. I had to go get her from the Controller's office and tell her it was time to leave. She still tried talking to the CFO who walked up. I told her "we all know how you feel so let's go".
When she was gone everyone was laughing at her. Because she didn't see that quitting without notice was not professional either.
In another case of lower level employees sticking their feet in their mouths. Interns fired as a group for trying to change dress code.
https://www.yahoo.com/style/interns-get-fired-en-masse-after-protesting-dress-201632030.html
Obviously, someone in management agrees that her actions were justified, or at least didn't require firing her. And if you read the article, she was aware she could get in trouble and had the personal integrity to take the risk.
There are things more important in life than any job. I don't think I would have reacted the same way in this particular case, but I can imagine other situations where I would. I have a hard time imagining Disney doing something that would rise to that level, but who knows.
We just need to distinguish the cases where employees are fired for being foolish from the cases where they're fired for having integrity and ethics.