In this article I am going to left apart the prize since it depends too much to say ‘USE GNU/LINUX IS FREE’ and I am going to center on the four freedoms of software: use, study, share and improve.
I think the education system should promote free software because it allows teachers, students and other involved members of the education community to study the used software and further improve.
It also does not generate dependency of features or programs that you can only get for a prize out of the education system, leveraging the students capability to use those programs or services in their future live in their cotidian live, work or to create enterprises based on those technologies without a great cost.
Students should get familiar in the basic levels of the public education with programming and the usage of the GNU/Linux command line and with the computers associated culture to build better digital citizens who valuate their privacy and other digital rights.
If you give Gmail to a child you will build 1984, but if you give them GNU/Linux and the four freedoms you will build a rich digital society where people is able to administer their own services and build better yet free software tools which may help everyone. (But without any warranty because they will be licensed under the GPLv3 or MIT.)
I hope the next time you give a course you consider using a free software platform like Moodle + Jitsi over a privative of freedom one like Edmodo + Zoom.