I do think people who haven't worked with 2020s middle schoolers would struggle to imagine how difficult many of them find reading at all, much less reading of reference type materials and on paper no less. Really while you should definitely give them something to work off of, the assumption should be that they'll drop it almost immediately in favor of making up their own stuff, and probably mostly their own rules if there isn't an experienced player at the helm. Kids these days are just as creative as they ever were, especially when its in service of not having to actually read something.
On two seperate occasions when I was doing summer camp D&D I came upon small groups of kids that told me they were "playing D&D" with no books, character sheets or obvious rules whatsoever. Just rolling a d20 for a broad sense of whether their characters succeeded or failed in the DM's story and doing whatever they liked.
In terms of simpler games you might also consider Bugbears and Borderlands. It's a simplified 5e clone. The pdf is available for free and the creator is a frequent ENWorld visitor. It also is perhaps a little less explicitly geared towards those with old school D&D nostalgia, something most your students will presumably not have, than something like Shadowdark.