To try and answer you question Mon-K I think that there is some urge there to do that and there kind of always has been when making cartoons. Every thing from shows like PPG to Ren and Stimpy are filled with things like that. More so with the other half of the spectrum. I use to think people were talking shit when they said Ren and Stimpy were gay, but then I went back and re-watched the show and I can't believe I missed it as a kid, it was hardly even subtle and sometimes not at all. Most other cartoons are a lot more careful with their adult humor.
Here's the funniest part in any PPG episode: https://www.youtube.com/watch?v=6VjNjJ5Xkqs
I laugh every time I see that scene.
I think that the creators of MLP: FIM are trying to appeal more to an older audience, but by a little. They want to acknowledge us while also not completely changing the show.
For instance we all gravitated to the idea of AJ's parents being dead and AJ having to take care of her family and farm with her big brother because it was interesting to us. The creators noticed that and they did it with subtly. The twin shooting star when I realized what it meant was so beautiful yet so subtle and it was brilliant and the fan art it helped inspire is just as beautiful.
So I think you are right Mon-K, but they're just doing it at a subtle pace.
I would like if they make a G5 series to grow from this point and tell more mature stories that don't take themselves to seriously, but take the audience seriously. Even G1 managed to get dark from time to time.