This lecture is now teaching a new approach to adding a user to a supplementary group:
groupmod -aU user03 group01

The new method certainly works but the lecture no longer shows the traditional approach with `usermod`. This creates a knowledge gap for the GE that follows which still focuses on the traditional `usermod -aG` method.

In my opinion, the traditional method should still be explained in the lecture and then the GE can be left as is.