Since you have travel and accommodation that can be cancelled at no cost, I wouldn't stress too much now. Travel was still happening yesterday from China to South Korea (the ABC correspondent, ours not yours, did it then), and if that hasn't stopped your arrangements are far less risky. What you might want to research is travel that doesn't involve both Korea and Japan so you only have to worry about one country. So, if Delta has US to Tokyo flights rather than via Seoul, think of changing that. Ultimately, take wide advice, not just us in here.
Edited: I was seriously looking at Cathay and JAL to travel for Palm Springs and would still be but for a Qantas deal for bonus elite credit for flights booked now.