Cory Doctorow’s ‘Little Brother’ only has 1 sex scene and it’s a pretty good model for sex positivity, I guess. That aside, it’s definitely near-future dystopia. Not far off the mark from today.
Octavia E. Butler’s ‘Parable of the Sower’ may be a bit above their level, but I could see 13 and 14 year olds devouring it none the less. Hmmm… there might be a steamy sex scene in this one too.
Technically Ender’s Game is a dystopian sci-fi novel. The film omits some insanely important content like a video game that the cadets all use during downtime that explores their psyche.
It’s old, but was my first introduction to dystopian concepts: The Time Machine by HG Wells
Oh, my wife loved Z for Zachariah at that age and reading it as an adult was enjoyable for me. A classic post-nuke young adult book.