It is a breach of copyright to republish any of the materials anywhere. This includes any re-publishing that leads to them being accessible by just searching the web. What that means is that students and teachers need to understand that them re-publishing the materials anywhere is breaking the law, and if they are placed on a classroom page of any description (Moodle, Canvas, Schoology, Powerschool, class or school website etc.), it has to be password protected and secure. The overriding question is SECURITY! Any violation of that policy is illegal.
It is also a breach of copyright for materials or subscriptions to be used outside of the school where they were purchased. One subscription PER school, and no sharing by students or teachers outside of that single school. All violations of that policy are also breaches of the law. Copying for the express use WITHIN your classroom is allowed.
Obviously I expect teachers to USE the materials! That’s why you purchase them. As long as you are not re-publishing the work outside of your classroom you will not be in violation of any copyright. If you, or your students do so, then put simply, that is a violation of the law.