IOS and MAC OSX devices will not automatically connect to a new SSID. It is a know Apple issue and that is what you will need to put a notification at the end of the onboarding for those users that they will need to manually connect to the New SSID. If it is same SSID onboarding then yes it will automatically connect with the link that Victor provided.
There is no issues with Windows and Android to change to the new SSID, only Apple.