Hi, servers in PoE are a bit different from others.
You just play on one with best ping to you. But you can chat with anyone, also you can party even with people from NA, but then it depends who is first in target location. This determines on what server the location will be.
So for example you are on Singapore and I am on Europe. We party together. You come to location where I am and then join Europe server - which means possibly greater ping...
But still it is possible. So everyone can be in touch with whoever they want.