What will happen to my Cisco Meraki device if the license is expired?
You must have a license for every device.
Your organization will go into license violation mode.
In theory, it will continue to run as per normal when your license expires. (You get a 30 day grace period to be out of license compliance.) You'll need to update/apply a license within this grace period otherwise at the end of the 30 days you'll organization will be disabled and the appliance will stop "Working".