Cutting Jang out of the footage could be a strong indication that his reported purge is true, analysts said, adding North Korea did the same when someone fell out the regime's favor.
Back in 2010, the North reportedly executed Pak Nam-ki, former chief of the planning and finance department of the ruling Workers' Party, over its botched currency reform the previous year, and then eliminated him from all documentary films.
Though the communist country has remained silent about Jang's fate, the re-run of the documentary for the first time in 40 days appears to be Pyongyang's deliberate act, according to the analysts.
"His disappearance from the video indicates that he would not make a comeback in the future," said Chang Yong-seok, a senior researcher at the Institute for Peace and Unification Studies at Seoul National University.
"I think he would not attend the scheduled ceremony on December 17 to mark the second anniversary of the death of Kim Jong-il," he added.
Kim Jong-il, predecessor and father of the North's current leader Kim Jong-un, died of a heart attack on Dec. 17, 2011. The anniversary is a major event for North Korea and its leadership.
The researcher also noted that no major North Korean figures have returned to public life after their images were cut out of documentary films as Jang's. (Yonhap news)