Yes, all sections sent from the SIS to Clever will appear as classes.
To prevent classes from appearing in Learning.com, filter the list of sections in the SIS or on Clever. If for some reason it is not possible to make a change in the SIS, but the class should not be seen by students (ex. a class name that has “Special Needs” in the title), a teacher can hide a class from students by not assigning curriculum items to that class. The teacher can create an un-synced class and assign curriculum items. In the new class, enrollments will not be automatically updated because the data is not synced to the SIS. If there are changes to the enrollment, they would need to be handled manually.