Anachronism Stew: Despite this episode explicitly claiming this episode takes place back in Season 4 (1992-1993), Itchy and Scratchy has a Dancing with the Stars parody (which didn't air until 2005), and characters based on the Minions from Despicable Me (which was released in 2010) appear in a theme park. While the Simpsons do exist in a Floating Timeline, this just makes things rather confusing, especially since the original episode made explicit references to Princess Diana and early 90s tennis players.
Cerebus Retcon: Somewhat downplayed. While the camp in the original episode is shown to give horrific treatment to campers and have terrible living conditions, the episode never took it TOO seriously, at least not to the point you would expect major psychological scarring. Also, the rebellion is portrayed as justified catharsis and a relieving change of pace from the nightmare that was the camp. And once Krusty comes and saves the day, this just seems more like an experience that the kids would remember, but succeed in the end. The idea the events would come back to haunt them was almost definitely never intended.
Faux Horrific: As part of the overall Retcon, some of the "cruel" things the Kamp Krusty children were forced to endure include a production of The Parent Trap by the drama club.
"Flowers for Algernon" Syndrome: Due to the traumatized kids interrupting his sex life, Homer decides to go to work early and finds that without the distraction of sex, he's become a more efficient worker. Eventually, however, Marge begins to miss the old Homer, who may have not been as smart and ambitious, but was certainly better in bed.
Retcon: And how. This episode contains so many inexplicable changes from the source material that it is heavily debatable how much of a sequel this episode even is. Despite having the same writer as the original episode, it does not show. We cannot expect a writer to remember every detail about a previous work, especially from almost a quarter-century later, but we would have expected him to have at least watched the original episode before doing a sequel.
To start, there is a Happy Ending Override...in the original, Krusty saves the campers (despite their suffering coming from his own negligence) and takes them to Tijuana, and all is forgiven and forgotten...until this episode. In this episode, the kids are finally returned, but they are scarred and shaken, as if the trip to Tijuana never happened.
The kids are seen canoeing in a flashback, and it becomes important later, but a scene in the original shows the rivers too dangerous to canoe.
Marge and Homer act as though the rebellion never happened...even though they already saw the news report about the camp being taken over by Bart.
Jimbo, Dolph, and Kearney are seen rebelling against the camp, even though they were the counselors against whom the campers were rebelling and were reported as missing during the chaos.
Mr. Black is nowhere to be seen or even mentioned, despite being the cause of all of it.
Nelson is seen coming off the bus in this episode, despite not being a camper in the original episode.
Sideshow Mel was seen in a camp flashback, even though he was clearly not present at the camp in the original episode, nor would there have been any reason for him to be there.
Most importantly, the slave labor, cruelty, and starvation the campers went through is never mentioned. Any memories of the camp are to things that never happened in the original episode, and were not really cruel except in a hyperbolic satirical way. For example, instead of Lisa saying they were fed gruel and made wallets, she brings up how they were shown the Parent Trap or were forced to watch the camp production of Phantom of the Opera.