Did they really think protesting was an effective way to gain future employment?
Most of us have worked with people who feel the world owes them something and I don't think there is any need for conspiracy theories here related to the timing of the protest. Its just bad judgement by this group of people who now will have no chance of being rehired.
It's good for Orbite to know who the trouble makers are before hiring and being stuck with them. However, I suspect these people had identified themselves in their earlier time at Orbite prior to this stunt and hence the notices of termination.