That’s a very good question – but then there are a lot of very good questions. This update could have just been about bug fixes, but maybe there’s more to it than that.
For those of you playing at Christmas and Valentine’s Day, you’ll remember what happened when the update came through and most of your friends hadn’t updated yet. You couldn’t access their towns and collect coins or hearts – and mob rule was the result on the official Facebook pages and on the forums.
EA took a different approach with the St. Patrick’s Day update. There was an app update in Monday afternoon US time, but the event didn’t actually unlock until Thursday. This gave everyone a few days to update their apps.
Without Origin yet on Android devices, though, this may not be the full reason (it’s been promised since August 2012 but there’s been no news of when it will actually happen). But it certainly seems to be part of a new game update pattern.
Update: I’m getting a large amount of some fairly unpleasant abuse for not mentioning the hack this update apparently repaired (either before or after the event). That this blog doesn’t cover cheats or hacks is a moral choice. If you can’t respect that, then you’ve come to the wrong place.