There's tons of jokes floating around 9/11. I haven't heard many Gaza jokes, but hey the difference between comedy and tragedy is time so maybe Lando's clock was a tad fast.
It doesn't make sense though, because in 9/11, two thousand people died; in the school shooting, 20 kids and six adults will die. Yea, it's been just over 11 years since then, but will people be joking about 20 kids gettting shot to death 11 years from now? I don't really see it as a matter of time, but as a matter of who died. When 20 kids are shot and killed, nobody will joke, but they will when two thousand people, mostly adults, do die.