I almost always pushback and taxi before I receive the final load data. That is the way my company operates. It has to do with the lead sending the load information to load control, load control's entering the data into the system and the final numbers being datalinked to our flight. Most often it all comes together and we are ready to roll into position on the runway when we arrive.
At some stations delays are normal and I advise ground control on the way out that we may not be ready at the end so they can sideline us if necessary.
Sometimes less experienced crews get caught and block departures. They soon learn.
Happy Landings