Whoever thinks that Yuna is not motivated, Yuna 2010 Worlds or 2011 Worlds, now THAT is unmotivated Yuna. Yuna 2013 and 2014? Not at all. Whatever the motivation is, she IS very motivated.
I have no doubt that Yuna will be in 2018 Olympic games. She'll be all over it-all sort of promotion stuffs, opening ceremony, quite possibly the torch lighting, even the medal award for figure skating and gala. I'm pretty sure she'll be featured in the 2014 olympics closing ceremony where they show the promotion for Pyoungchang olympics.
It's just she won't compete there. She made it pretty clear this is her finale. And she can be very stubborn about things according to her mom.
She is not that short-sighted. She knows she can't babysit Korean figure skating forever, and she's more into nurturing the next generation of skaters and keep them going.