You say "the last one", but this is the first major event the game has had, everything before this was mini events to tide people over while they fixed bugs and got 1.1 ready. They'll keep it up for sure, we have already seen screenshots and have gotten spoilers from the 1.2 event, and it sounds just as epic as the current event. There's at least 4 acts, another Sage crown up for grabs, lots more cutscenes and focus on some characters that so far haven't had any focus yet. We'll probably keep getting 1 of these in every patch, or at least every patch that isn't a brand new full region, they likely want to keep Sage Crowns on a timer of about 6 weeks (aka 1 per patch) similar to how boss mat talent items are on a 1 week timer.

It's an exciting time for sure, and I hope a lot of the doomposters either realized what the game does well by this point or just quit to find some other game to complain about. It's great to see a post like this highly upvoted instead of the same old complaints about things that will not change.