I haven't done this myself, but certainly would, even if the material was a bit less "mature" than having been submitted. However, I would also inform the students that this was happening, though not that I had doubts about it. If I had doubts, I'd want to resolve those first.
If I were giving them written drafts or notes, I might even be inclined to give some bonus points for errors found or places where explanations confused the students. Sometimes our best efforts at explanation miss the mark. But students can catch that, perhaps better than expert reviewers who might have the same bias as the author.
I think that for a graduate course this would be extremely natural to do. A bit less for undergraduate, but I wouldn't arbitrarily exclude that.
For a text book in preparation, it is very useful for students to suggest exercises based on the material. It is a different way of thinking that can be as valuable as actually doing exercises. But, again, probably more relevant at the graduate level.
I'd know that I experienced it a bit on the student end during my studies. In fact, one of the best math courses I ever had was in my second year of undergraduate where the professor gave us material from a book he was working on. It is one of the things that solidified me as a mathematician, actually. But he was clear that this was his "work in progress".