Earlier quoted context omitted.
> give the cover story more plausibility Do they need to? Many employers would rather publicize it: we don't tolerate a union.
Retaliating against someone for trying to unionize is a violation of the National Labor Relations Act, as well as New York state law (Kickstarter is headquartered in New York) – hence the need for a cover story.
The company gets to have it both ways. Send a message that unionization isn't tolerated, while saying in court that unionization had nothing to do with the firings.