Hanoi was listed from 2004 to 2006, and then removed as a reward for limited liberalization. Vietnam remains the only country that has changed its laws explicitly to get itself removed from the roster. The government made it easier to register religious groups, dropped some egregious policies such as forcing believers to renounce their faith, and improved its relations with the Vatican.
The Bat Nha example exposes how prone to backsliding Hanoi is if it’s not forced to follow such early steps with further progress. Now is a good time to ratchet up the diplomatic pressure again.