Do the founders get the equity in the meantime before the future "stripes" are granted? e.g, let's say after two rounds of 10% employee equity, the company get

Do the founders get the equity in the meantime before the future "stripes" are granted? e.g, let's say after two rounds of 10% employee equity, the company gets acquired, leaving 30% that had been set aside for future rounds of employee equity, but never granted. I'm assuming the founders would split the remaining 30%? Curious if anyone had insight into why this would not be the case.