Wi-Fi sharing with iOS11 and the risk to the enterprise

In the instance where there is no certificate or ‘other’ authentication for Wi-Fi access, what will stop an employee sharing Wi-Fi credentials, provisioned through EMM or not, with a non-authorised person?

Apple made new restriction available that addresses this concern

Allow setting up new nearby devices
Users can’t use their Apple devices to set up and configure other Apple devices.

http://help.apple.com/deployment/ios/#/apd879d60c3d