Two things: First, remember that the Winter Games stuff came out almost a whole week after the Olympics started. There were problems, and that prevented them from putting that stuff out "on time". So they will indeed delay introductions if necessary. Second, beyond the technical, another major contributor to the timing of the introduction of features is marketing. As alluded to earlier, there were PR issues with how the Valentine bonuses were introduced, and so our best info is that the delay in the introduction of the second-tier of St. Patrick's Day bonuses is a deliberate, marketing decision, aimed at having something to make a big deal about this coming week.