This theory (in multiple variants) is at the bedrock bottom of modern biblical criticism. That doesn't mean it's right, but it's also consistent with Nephi's horrible account of the rewriting of the Israelite record (the revisionists remove plain and precious things from the record; the tree that is the city Jerusalem and also the Virgin mother is the most precious thing), so we should take it seriously.
To date, this understanding has had approximately zero impact on Mormon Sunday Schools. If you want to explore it, your on your own; so here are some books to start with:
- Moshe Weinfeld, Deuteronomy and the Deuteronomic School. This is a classic -- out of print, but still available secondhand.
- Moshe Weinfeld, Deuteronomy 1-11 (The Anchor Yale Bible). Weinfeld's commentary on Deuteronomy is being republished posthumously. The 85-page introductory essay alone is worth the price of admission.
- Bernard Levinson, Deuteronomy and the Hermeneutics of Legal Innovation. Should win some kind of prize for its title, but this is a terrific book about the way Deuteronomy rewrites earlier legal sources for its centralizing ends.
Again, there are many more books on this key topic. These are just the ones I own. A good introduction to the Old Testament (by "good" I really mean not tied to any church, but especially not Evangelical) will also give you some background.