That still does not give the company the right to fire them, which is the law man... And the company could recognize the union if it wanted. So a vote is not mandatory.

Note the subject of the post: "Kickstarter employees fired for trying to unionize". That's either true or it is not and so far you have not brought anything to the table that suggests it isn't retaliation for exactly that, and in fact substantiated numerically that the chances that it is not retaliation are vanishingly small.

They aren’t independent samples though. They could all have gone on a downward spiral of disgruntlement at around the same time (on the order of months), and then once management finally got around to doing something about it, they started the termination processes at the same time (on the order of days).

I think pressuring for a vote early is of benefit because another vote can’t take place for some time period afterwards. The organizers want to stall a vote for as long as possible to work up support before this happens. While it’s illegal to fire a worker for trying to organize, it’s entirely legal to fire that same employee if they are violating company policies to further that organizing effort. I don’t know that this is what happened but is often the case I’ve seen. Misuse of company resources, disruptive behavior, not completing tasks, using paid time to do union work, bad for morale of other employees, creating hostile environment for other employees, etc.