Interesting question... And here's the way I see it. Once a company "releases" you, or requests a release from the CAAC, you are free to go/do whatever you want.
So did you leave your old co. in OK terms? Finish contract, did not steal too much silverware, left pregnant FA's, etc
Just kidding!
And if so, was the CAAC notified? That's my understanding. Maybe others could add their knowledge here...
Hope this helps