It was a ludicrous notion. The Devs would have told us months ago, if they were planning this, and they've said nothing to suggest this at all. In fact at the end of last year, Deep said there were still a lot of stories to tell, which hardly sounds like he's winding down towards the end. In the last few updates, they've introduced new characters, and new storylines, as well as suggesting others ( like the search for Alfred's daughter). Everything points, towards several more years of development to come, plus as you suggest a third volume of the game.
Deep has said Anna will have other stuff to spend her money on eventually. The most likely is a car, since she's talked about this a few times. She's also talked about going on vacation, which might be interesting, since they could also introduce new characters who would only feature during her holiday