This is a problem I have yet to see schools tackle. A kid in junior high school has no mental context for the Russian Revolution of 1917, for instance. Having them read Animal Farm is a pointless waste of time.
Poor choice. Animal Farm is way, way more than an allegory of one historical event. It's a broadbrush statement on the kind of people likely to seize power at every opportunity (or if you prefer, the effect unrestrained power has on most people), and a humorous jab at authoritarianism.
The other books mentioned (Gatsby et al.) really require context, but literal pigs sitting down to dinner with powerbrokers is something a 14yo can grasp.
Same with things like (picking at random) The Great Gatsby and a lot of literature having to do with adult relationships and romance. How on earth is a 16-year-old in 2025 going to understand what's happening in Gatsby? I read it, wrote some papers and got As on them, but didn't really make sense of it at the time.
In addition to being a short classic, I think teens could identify with Gatsby being obsessed with getting the approval of people who have nothing but contempt for him. There's a devastating scene at the end where the narrator, Nick Carraway, organizes a funeral for Gatsby and literally none of his friends show up. I think that might resonate deeply for more than a few teen readers.
The Great Gatsby is an Americanized version of a Greek tragedy, I don't think it's too hard for a 16 year old to understand. It's no "Rabbit, Run", at least.
That's more a commentary on 2025 than 16 year olds I assure you. In the 90s adult relationships weren't particularly mysterious to your average 16 year old.