Updated the app in beta channel, currently USA only, to be available in Italy as well, using the instructions at Possible to limit the countries an iOS application is released to?
How much time it takes the app to be visible in the newly updated country? How would I know if/when the change was effective?
Well there isn't any specific time constraint limit, set/committed by Apple for this (or any other) process. The time they take to process you update, depends upon rush/queue of application submission and updates on store.
There is a small window of hope, provided by Apple, if you've an emergency or urgency to update your app (country list) on store.
Send a request to Apple using your developer account and contact CSR team. They will definitely listen you and consider your request.
I hope this may help you...
