Youtube url isn't seen in student's preview in the same way than author's preview

When an author adds a youtube clip using Add Content -> Embed Content and fills in the url, he is able to see the clip on the preview page, but any student only is able to see a link "Open in new window".

To reproduce this issue:

• Set the following properties:
  lessonbuilder.basefolder=Lessons
  lessonbuilder.folder.hidden=true
• Add a youtube clip
  The author is able to see the clip on the preview page, but any student only is able to see the clip clicking on the link "Open in new window".

We think in both author's preview and student's preview, it should be seen the same preview page.

We've solved this issue hidding the main content folder of Lessons but keeping the content accessible to students.
SimplePageBean line 5425:
-edit.setHidden();
+edit.getPropertiesEdit().addProperty(ResourceProperties.PROP_HIDDEN_WITH_ACCESSIBLE_CONTENT, "true");