Changing AppleID Countries & potential loss of data

In the legal documents: Legal - Apple Media Services - Apple you will find, "When your Paid Subscription to any Service ends, you will lose access to any functionality or Content of that Service that requires a Paid Subscription."

You are not only letting the service end but you are also changing to a different iCloud service. I would therefore play it safe and ensure you have independent backups of your data. I have never changed country with Apple so I don't know exactly how they handle it. There is a possibility that your data may somehow survive the transition but there is nothing I can find in the documentation that guarantees it.

Apple Support Communities is set up as an end-user to end-user technical issue support service (i.e., users like you helping other users). Feedback for Apple will likely get more attention if you send it using: Product Feedback - Apple

I have a similar issue. I actually live in BOTH Canada & the US, and I occasionally need access to apps that are NOT in the app store of the country that I'm in. But in order to CHANGE COUNTRY to access the correct app store (ONLY for a simple, single download of an app), I LOSE my AppleCare subscription, and I'm not permitted to restore or renew it. I'd like Apple to consider allowing people to MAINTAIN their AppleCare subscriptions (or renew them), if only for 24 or 48 hours, or, even better, until their subscription period ends, if, for these interim reasons, we need to change our country or app store.