You're assuming that each of the four members get similar dedicated v0.xx.5 storylines like the community characters have seen recently and nothing else. That's not how it works. The family gets focus during the v0.xx.5 but that doesn't mean they get completed stories specifically in any of those. Also, Leslie gets some kind of content every release, with "consummation" sometime around v0.10 or so. But even that doesn't end her storyline.
However, it may take 4, 8, 12 years or however long Breadman wants to make the game. He may decide he's done after 2 years. He may continue making content for the rest of his life. (I am not trying to speak for Breadman). I wish people would see adult game updates more like episodes of an ongoing tv series rather than something that has a "You Win. Game Over" screen as a goal.
Are there really that many completionists? Why would anyone want something good to end? "I'm having a great time... I can't wait for the developer to wrap it up so I don't get new content ever again."