Hello Rock99V,
Thanks for using the Apple Support Communities!
This is a fantastic question and I thank you for asking it! I understand that you are curious about what happens to your previous purchases and subscribed services like iTunes Match when you change countries or regions.
First, when you change countries or regions, you will no longer be able to see the items that you purchased from the previous country’s store in the Purchased section of iTunes as described in the following article.
What you need know before you change your country or region
When you change your iTunes Store country:
- You need to update your billing address to one in your new country. When you change your billing address, the primary address in your account at My Apple ID and your other Apple services, such as the App Store and iCloud, automatically updates.
- You might need to update your payment method. For example, only German credit cards can be used to buy content from the German iTunes Store and App Store.
- You won't see the items that you purchased from the previous country’s store in your Purchased section.
- You won’t see the items from your iCloud Music Library that you matched, uploaded, or added from the previous country’s store.
Change your iTunes Store country or region - Apple Support
To ensure that you keep access to all of your previous purchases, you will need to make sure you have downloaded all of your purchases to your computer’s iTunes library before changing the country or region. To accomplish this task, please follow the instructions for On a Mac or PC as described for each category in the article.
Download your past purchases - Apple Support
After you have downloaded your entire purchase history, I would highly suggest backing up your library as well to ensure that you have access to this purchased content if something should happen to your computer after you move.
Back up your iTunes library by copying it to an external drive - Apple Support
You also mentioned that you are an iTunes Match subscriber. According to the next article, you will need to wait for your iTunes Match subscription to expire before will be able to change your country or region.
iTunes Match subscription or Apple Music membership
If you subscribe to iTunes Match or have an Apple Music membership, you need to wait for your iTunes Match subscription or Apple Music membership to expire.
You might also need to turn off Auto-Renew for iTunes Match or turn off your automatically renewing Apple Music membership.
After your subscription or membership expires, you can change your country.
If you can’t change your iTunes Store country or region - Apple Support
Cheers!