In the CS bachelor degree I'm responsible of, we have exactly that in the third and last year (it's in France, so as in ~all Europe the licence lasts three years and then students continue their studies doing a master in two years).

I've been teaching this course for ten years now, and it's been fantastic. A lot of open source contributions, mostly trivial, but some more significant than others too, have been made, to a lot of different projects. It teaches students to actually work on a real code base, using a real workflow (fork, clone, branch, commits, PR, review, commits, review, … hopefully merge), talking (in English) with maintainers, having to update tests and documentation not just code, and having to respect a lot of conventions that are not always explicitly listed anywhere (a first work that I always ask them to do is to present the project they have chosen, its tools, platforms, and languages, and to list all the programming conventions (indentation, naming, etc.) they can identify). At the end of it, it also make them realize what they can do, because at the beginning of the semester most of them think they will never be able to actually make a contribution to a real project.

This year only there were contributions to NewPipe, Cartes.app, Immich, Fossify apps, PyGameEngine, Jax, Shortcut, Wikimedia Commons App, Godot, …

Some years ago I even had students contributing to ls (yes, in the GNU core-utils).