To be frank, I don't think that matters much.  The user should understand what a lock is already, if they want to make use of multiprocessing fruitfully.  The example showcases how to create a lock and how to pass it to child processes (by giving it as a function parameter).  Printing to standard output is not the important thing here.

However if you want to improve this example, you could replace the acquire/release pair with a "with" statement.