SpaceX will never have an IPO because being publicly traded means ceding a certain degree of control. The founders' goal is to make life multiplanetary, and the typical goal of rando shareholders is to pump up the stock price. They don't want to have to deal with the latter. They may at some point spin off Starlink and IPO that, but not until it's fully deployed and not heavily dependent on frequent, super cheap, low bureaucratic friction launch services from SpaceX.