Client no longer supported in this country…

That depends. Are you playing as a "guest" aka a local account? If so, yes, poof, all gone as the data is stored on your local device.

If you are like MOST people and play using EA connect, Google Play or whatever the apple version is, than no.
Your data is stored on the servers, not your local device.

Best be sure before you uninstall.

Poodle is correct. 

no i have done so myself

I got the same thing. If I delete the game, will I lose my progress and characters when I reinstall it? 

Delete the game and reinstall, worked for me

Same… has to be with the latest update. They borked something. Not good at all. 

Got the same bogus error as well...