Will North Korea use King as a bargaining chip or perhaps a propaganda tool? The reality is, according to Washington experts, that the North is less interested in getting short-term gains by releasing him. However, another question is whether or not he should be viewed as a valuable asset given his low military rank.
“King could either be a bargaining chip or a propaganda tool. If he desires to stay in North Korea for fear of punishment awaiting him in the U.S., he would probably become the latter. Once Pyongyang decides on an approach, they will reply to the United Nations Command’s (UNC) attempts to discuss the matter,” according to the Korea Society director.
Over the years, there have been a number of U.S. citizens who have crossed the border separating the two Koreas. These people were mostly human rights activists, missionaries and, from time to time, soldiers. On occasion, based on the weight of each incident, the North Korean regime has used political tactics in its handling of border crossers.
The widely-known cases are the defection of Charles Jenkins and James Dresnok back in the 1960s, both of whom were featured in various North Korean films as “U.S. villains.” In Jenkins’ case, for example, he thought he would be traded to the Soviet Union and then back to the U.S., where he would serve time in jail ― which he preferred over possible deployment to Vietnam. He was held in North Korea for 39 years, where he was tortured and used in propaganda.
Korea Times
You can read more at the link, but I think this decision is really dependent on King. If he is willing and enthusiastically embraces being a propaganda tool than North Korea will probably keep around while he is still useful. The minute he is no longer useful is when they will deport him.