Update process confusion!
If you change your region for your Apple ID and iTunes store account, there is no guarantee that the apps you had paid for and downloaded will still be downloadable since you are literally shopping in a different store with different app availability.

Now, common apps like Evernote and Apple's apps are generally available in all of the countries, but many smaller developers focus on one or two countries and the switching process can mean you lose apps.


http://support.apple.com/kb/HT1311


Is there a specific app you have found that is available on the new store, yet your account will not download? If so, I would contact the App Store support team to ensure your switch was properly executed on the server side.


http://www.apple.com/support/itunes/account/


Look for the icon like below that's about 2/3 of the way down the page currently.

It's possible they are rolling out changes in preparation for the announced iOS 7 changes where moving VPP purchases becomes easier or perhaps it's just a bug. One thing's for sure, not everything that changes gets announced, is permanent or immune from a rollback if it doesn't work as planned.