I have a workmate who buys lottery tickets from time to time and he loves what he does here so much that he said that if he won big money on the lottery we wouldn't even know or notice. And I believe him when he says that.
Well, I don't work with this aspect of the mission, only with one of the data indexing and visualization solutions. This is just the first data release, not all data acquired by the satellite was included in this data release, some are still to be processed. Besides, Gaia is orbiting the Sun, not Earth so each parallax measurement of a star is 6 months apart and to increase the precision several measurements must be taken (so I was told, I am a software engineer, not an astrophysicist).
Actually counting and identifying the stars it the "easy part". But it takes time and several observations of each star to get information about the variable attributes, like proper motion, flux variations, etc. Most of the stars used don't have a reliable measurement of parallax and/or distance, only about 2 million stars have parallax measurements (most of them derived from the Tycho2 catalog from Hipparcos mission). The goal is to have all the attributes (or most of them) for all the stars, reaching one petabyte of data.