I loaded the Sim to try this out. (Testing at KDTW: Map Zoom 1 mile.)
I notice when changing servers players do not change on the world map, unless the game is restarted. That seems to be when the map hooks to the server. I’m pretty sure servers change after hitting the ‘Fly’ button. Haven’t tested that yet.
For the images below I restarted the game after changing servers.
KDTW North East USA
KDTW South East Asia
KDTW North East USA