Updating Learning Paths question

I just tested this in my sandbox, but I’m not confident in the results - 

We just released some updated courses today that will affect existing learning paths, so I need to go in and add the newly released courses to those learning paths (& remove the old courses). How will this affect any existing learners in those learning paths? Will they have the original courses that they signed up for with the learning path? Or the updated courses?

I’m not finding the answer in the Setting up Learning Paths article so it’s making me nervous…

Thank you!