I hope he can shake this off. WTT isn't a big deal but of course he wants to always skate well and he always wants to perform well for Japan.
Everyone has off days, no one can be perfect all the time. He just needs to sleep it off, and start tomorrow as a new day, step out for the free as a fresh start and try. Even if he doesn't do perfect in the free, it's fine, WTT doesn't matter. Pretend it never happened, say goodbye to both programs and focus on next season.
I really hope over the off season he looks into different ways of getting a good mindset for himself; focused but not too intense, comfortable but not too relaxed, confident but not cocky. Calm. Not over thinking. Just doing.

I just want to give him a hug and tell him its okay. 1 bad skate doesn't mean anything or change anything.