When new classes are created and teacher are assigned, a notification goes out the teacher by default. If you are spinning up a new studio and are in major class creation mode, this can be a lot of notifications.

To turn this specific notification off, follow these instructions. Click Studio-setup > Transactional templates > search for 'teacher' > click 'Class new teacher notification'

Disable the template using this toggle. Apply the changes at the bottom of the page.