in 1x13 Zhao says: "This is the year Sozin's Comet returns to grant us its power!!"
So my conclusion would be that the attack on Jeong Jeong (1x16) happens in 100 AG, because the comet is supposed to happen in the same year. Or was there any hint in the episode 1x16 that it clearly is in 99 AG?
Katara and Sokka found Aang some time near the end of 99 AG, and it took most of the season to get to the polar opposite of the world. The Siege of the North took place in around February(?) of 100 AG.
In other words, why fix something that ain't broke?
"Avatar Aang begins his firebending training with Jeong Jeong, however, his training ends prematurely when Admiral Zhao attacks Jeong Jeong's camp. " is written under 99 AG. If 1x13 is supposed to be in 100 AG according to Zhao, it means that "The Deserter" 1x16 (Jeong Jeong's episode) should be moved to 100 AG.