I heard this sometime and never once witness anything great or wonderous from this mythical "server community". That could be because I do not hang out in cities reading trade chat, except to try to find PUGs. I am usually out in the world doing stuff, like levelling alts, doing dailies or farming.
I am sure some people experienced this, since I heard this mentioned now and then but how big was this "server community"? Was it really that great or was it simply people knew a few others from other guilds because they raided with them or group with them regularly?