Cross-Data Center things

So when the new data center was made and servers got shuffled, I got cut off from friends whom I had been playing with. Added to the fun, there are no Preferred servers on their data center to move to (at the moment there is no space for even a new character).

So here's the thing, why not cross-data server world visit? It seems to be a temporary world transfer, it would seem feasible. I get not randomly assigning dungeon groups across data centers, but world visit is a whole other animal.