You can travel between the countries you hold a passport of regardless of what emergency rules they impose. No country refused entry to its own citizens during the pandemic.
Australia
"Japan suspends new reservations on all incoming flights" https://apnews.com/article/coronavirus-pandemic-health-japan...
This was a short lived measure but did have the effect of preventing some citizens from returning. It could be argued that they could travel by boat, but I believe most ocean travel was also restricted at the time.
Edit: assume via Singapore also doesn’t work?
De-facto they are preventing citizens from entering but de-jure they are still allowed. But I mean it's China, is anyone surprised here?