My opinion is that it was a good idea and great for the development of the series, especially since the learning about friendship and letters to the princess thing is three series old.
Everypony seem to be stuck with the idea that Twilight will be a ruler of a kingdom, but as a junior princess and the lack of free kingdoms it will mean more development in the magic area and/or showing her learning to handle her new responsibilities with a little help from her friends.
S4 may be Twilight getting used to her princess role if you consider Princess Celestia's response to "Is there a book I should read, on being a princess?"
It suggests that Twilight will be taught how to be a princess by the other princesses and possibly cover her friends ideas on how to be a good princess.
My opinion is that it was a good idea and great for the development of the series, especially since the learning about friendship and letters to the princess thing is three series old. Everypony seem to be stuck with the idea that Twilight will be a ruler of a kingdom, but as a junior princess and the lack of free kingdoms it will mean more development in the magic area and/or showing her learning to handle her new responsibilities with a little help from her friends. S4 may be Twilight getting used to her princess role if you consider Princess Celestia's response to "Is there a book I should read, on being a princess?" It suggests that Twilight will be taught how to be a princess by the other princesses and possibly cover her friends ideas on how to be a good princess.