I figured this would already be the case.
The problem I see with this is picking having high latency. I would hate to join in a Virus game that has been hosted in Sydney with 300ms ping.
I think it would be okay if they indicate the region they are from on JOIN popups and the Gameworld Port panels. But then again, the host selection actually decides the best host so it could also be a problem for those who would rather have a small smooth game than a large game with awful latency.