Venture Bros.

[Mothra]

Frocto sent this interview my way, which explained a bit:

Can we expect a big Venture Bros. style cliffhanger at the end of the season finale?
Publick: Absolutely not. It will be very disappointing as a finale. [Laughs] The same thing happened to us last season, actually. We didn’t have a big finish last season, because we shot ourselves in the foot. We basically ran out of episodes to get to the point of the story that we wanted to do a blowout ending for. So that’s why you ended up with the Gargantua special, the space special last season. That story would have been the hour-long or two-part finale of Season 5, but we hit our 10-episode mark before we got to it. So we did a special that bridged the two seasons. And the same thing is happening at this point.

The story we’re writing now would have been the season finale, but we didn’t get to it. We weren’t ready for it when it came time to write the last two scripts. And there was actually a little confusion for a while as to whether or not the Gargantua special counted against our 10-episode order, so we were writing like four different stories at the same time not knowing whether we had two scripts left or four. When it turned out we only had two, we were like, “Alright, I guess we should do our finale.” And then we thought, “No, we haven’t really earned it yet. We need to flesh out this Monarch arc a little more....” So we made a judgement call and wrote two other stories that we were very excited about.

[Thad]

That...really does explain a lot. Gargantua 2 felt more like a traditional blow-everything-up finale because that's what it was supposed to be.

And then season 6 doesn't get a finale either because it used up two episodes doing Gargantua 2.

[Mothra]

This one's for you, Niku.