People need to realize is that Yamato's whole character arc here is about NOT being shackled down. Her devil fruit being regarded as "The Guardian Deity of Wano" should further enforce the notion that she will leave the Country. Whether it be as a Straw Hat, or by some other means, she is leaving Wano. This is the same thing Oden went through being born as the Shoguns son, and the fact that the borders of Wano were supposed to be closed. He didn't want to be shackled down either, and chose to follow his own path. That is what Yamato is trying to achieve herself.