Going public is not always about raising money. Many startups are forced to go public because they have employees who want to cash in their stock. Once they become established companies, being able to offer stock options to employees is a considerable advantage.
In those cases, going public is a way to raise money to pay those employees. The company could easily buy back their shares if it had the cash available.
In other words, they planned from the beginning to go public in the future as a way to pay for their current employees.
