I think the concept is solid, and I have seen an attempt at this once, and thought about how to apply something along the lines to Anki.

There was, a long time ago, a post here with a learn Japanese, where you where shown a sentence if I remember correctly, you clicked the words you understood. Sentences where synthesized long before LLMs existed, so sentences weren't great.

And you want something that keeps track of words and grammar you know and present words you are about to forget in a context of words and sentence structures you are familiar with. This could even be two or three new, or forgotten words at once, and the system keeps track of multiple words per flashcard (or quiz, as the cards are fully dynamic)