Hi @jasoncrandall,
What you're looking to do isn't really in the standard functionality for Canvas at this point, as in my opinion it's designed more around one-time courses/assignments than things like a recurring certification. With that being said, there are some potential ways to go about this, and it sounds like you've already found the start to one.
While Canvas can't automatically reassign something itself, you could likely write an API script to crawl through the course and do that for you. You'd need someone with at least a little bit of API/scripting knowledge to do this, but I think it's possible. The downside of this method (again in my opinion) is that it may not be super clear to the "students" in the course that things have to be redone.
Another possible option, which we have implemented in a couple cases at my institution, would be to create new quizzes or completely new courses each year. You could have a "2024-2025 safety quiz" and a "2025-2026 safety quiz" and so on, or a "2024-2025 certifications" course and a "2025-2026 certifications" course each with their own "safety quiz". In Canvas itself, I'd say this is an easier method, but at least the way we do things someone could have to take the quiz twice in a short period (say they take it April 2025, we'd ask them to retake it again in September, as we just look at the results of the current year course/quiz). You could look at results differently to avoid this small complication, but it honestly hasn't turned out to be much of an issue for us.
I know this may not be exactly what you were hoping to hear. It's totally possible there are other solutions/ideas that someone else will post, but I at least wanted to get you an idea or two here to start with.
-Chris