Well, the April stuff goes down in 14x23 and the wedding is in 14x24. In the sneak peek for 14x23, just before April is brought into the ER, we hear Glasses (the intern that dicked Jo in the premiere) talking about how he wasn't invited to the wedding. So I'm guessing there might be a bit of a time jump between this week's episode and the finale. Still, I'm sure there will be some drama at the wedding. It's a Grey's finale!