If the source is removed Completely then there should be no more danger. Let me emphasize, "should be".
Don't take one persons word for it. Make sure at least 2 air quality tests are done.
I would suggest to contact the companies that specilize in chinese drywall, they should be able to clarify what and how things should be done to assure the property being a healthy environment in the future.
Since it is relatively new issue, I am not sure if anyone for sure can say that everything will be OK.
Probably the future will show.
Here is my four part trulia blog on the issue
Another common problem associated with these projects is when the tainted dry wall is removed and an immediate reapplication is done without thoroughly cleaning adjacent areas and allowing the the building to "breath" or air out for a considerable period of time.
Before considering enterinto a venture involving the rehabilatation of one of these homes we would strongly recommend a conversation with a contractor that has experience with this type of project.