Because they don't care. As long as people buy the themed items on the marketplace the event is a success.
It's not on test yet because they don't have it ready for test, or else because there's no new content this year that needs testing.
Most of these events seem to be some sort of switch that gets flipped when the time is right. Unless they've added new content to the event then there's no need to do anything other than turn the event on for the server. I wouldn't be expecting a whole lot in the way of new content for the event that isn't marketplace related.
Ask, an ye shall be given: https://forums.daybreakgames.com/eq2/index.php?threads/erollisi-day-feedback-and-bugs-2018.583787/
Yeah, Test had to get the Weekly update before getting the Erollisi Day update. Hence why it had been delayed until later yesterday. Glad it's there now! ~ Kaitheel