Let it go

Today I discovered that a book I had sold had been lost by the post office.  And I could not find the tracking number.
Grrrrrrrrrr.

So I had to trust the buyer's claim that the book never arrived and issue him a refund.

As I talked myself down from my annoyance I used the phrase "let it go".

And then I wondered....will the movie, "Frozen", change the way that phrase is perceived by the youngest generation?

Instead of meaning, "ease your emotional angst and stop focusing on this annoying or bothersome issue and free yourself to move on" will it be thought to mean "stop holding back and express what you are feeling to the nth degree"?

And what confusion will that cause between my generation and theirs when my generation suggests that they "let it go"?

And if it does change in meaning, what new phrase will we develop to replace the older meaning?