As far as not getting Grand Prix assignments next season, I'm sure there will be some concessions made in the rules to compensate for the unusual situation, especially in the case of YuNa, who's the reigning Olympic champion. They're not going to shut her out from competition next season, I'm sure. For one thing, it would effectively shut Korea out of much chance of doing well in GP events, and they're not going to close the book on an entire country--especially a country with such a huge fan base. It's nobody's fault that the World Championships had to be suspended. I certainly hope that skaters will as much as possible be spared from any unfair penalization if Worlds is not held, or is held late, and they can't participate for some reason.
YuNa isn't just a Korean superstar, anyway. She's a world superstar, one of the best skaters in all of history. (Some would argue that she is the best ever.) If there's any way for the ISU to bend over backwards to get her into competition next season (whenever Worlds is held), they'll do it, I'm sure. And if not, that's when we should start writing petitions again! Whether you're a YuNa fan, a Miki fan, a Mao fan, or all three, YuNa is an incredible gift to skating, and she should be accommodated in any way possible so that she remains in competition--not at the expense of any other skater, but just in some fair way.