I've been thinking... SethxZoe situation accidentally revealed something: Gabe doesn't have a plan.
Let me explain:
-Gabe said that the last image Seth worked on was the Queen's scene. which, at the time this scene was present was also the last scene in the story to show up and she doesn't have any other image.
-Seeing how not every month there is a new scene we can rule out the artists being called every month or so, so Gabe only calls them when she has a new scene planned. Gabe likely doesn't have a list of the scenes she wants in the game.
-If Gabe doesn't know what scenes she wants in the game, and they are mostly tied to the story it means two things: Either Gabe really really really wants to leave it last minute to decide which positions she feels like narrating... or she has no clue which nsfw scenes will appear because she doesn't know what will happen or what will the players encounter next.
If Gabe knew she would've made a list of the scenes she wanted for the story and sent them out to the artist so they could work in tandem, basically finishing all the main story art first and slowly incorporating it as the game develops and later adding extras or fixing small things (as this is a way to keep the attention of the artists, make sure the styles don't vary wildly, and avoids unpleasant surprises in the long run, in a 'hey, at least i have this ready')... if after almost a decade of development she doesn't know what scenes for the main story she wants because she doesn't know what scenes there will be it tells me one thing:
Gabe might have a plan on how the story ending will be... but that's it, she doesn't know any of the steps towards that finale.