Yes, you can create a configuration profile to restrict Modifying passcode under Restrictions -> Functionality and assign it to your student devices. You could then do a search and perform a mass action to clear the passcodes from those devices.
This will remove the passcode from the devices and prevent the students from setting it again.
Also, make sure that your prestage enrollment for your student devices has Passcode lock checked to not be displayed, so they are not prompted to set it during enrollment.
Hot diggity! Thanks, that language in the policy was a little less than intuitive to me...can't modify it unless it has been created first...hence my question. I did a quick test and that solves it!
Our prestage it set to only show Location Services to the user, so the other suggestion should already be handled.
THANKS!