While I won't rule anything out conclusively, I see no pressing need to add any more scenes with them to the game. In fact, I can't even imagine where I would add something like that without breaking the story structure.@Belle Is it possible that there will be more content with the princesses later on? For me there is way to less content with them and also i like Selena the most even i she appears only for a short time near the end of the game. Its sad that the name giving Princess only has so much screen time.
Selena was always intended as an endgame arrival. This isn't a game where all the girls are available equally, or even developed to the same degree. Compare, say, Erato to Evelyn, for example, and you'll see that they have vastly different amounts of content. This is by design.