I don't get it.

A passport is required to travel. By annulling the passport, the person no longer has a valid passport to travel. No sane airline would allow someone to board without a passport, or with a passport that has been voided at the Interpol level. So he couldn't travel and would have to stay in Taiwan, probably seek asylum there. Isn't this exactly the opposite of what the government intends?

Now, it would make sense if they would revoke the passport while he was in the US, to prevent from leaving. But to revoke while outside seems counterproductive.