Frankly, if they ever did allow for cross DC, they should just remove servers entirely and make mega servers. So you're on the NA server, in totality (or JP, etc). and can play/meet anyone on the entire datacenter. This would mean having more "Gridania shard 1, 2, 3" etc, but ultimately it'd be a better solution.

Then, if you're going to allow cross DC, should just make the entire MB entire-world level.

...that said, I prefer things as they are, although no I would not require anyone to prove their location in the world. As is many players from countries (like in South America) don't live in places with a DC. Restricting based on country of residene? SE would never opt for an option to lose revenue like that.