Why is the flight number relevant? I would agree if she made a threat but otherwise this is the action of an oppressive organization.
Airlines do this all the time. Punish customers who are unhappy with the service. It’s easier then providing a high quality service apparently.
It’s relevant because she made her name known with the airline the flight she was on. I don’t care what she tweets, or what she complains about, but she made herself visible with the tweet. That’s why it’s relevant.