I think I'm misunderstanding what you are saying here. There is always an announcement before servers go down and also a time as to how long before it does. Also mentions not porting, doing anything that may mean potential death when sever goes down etc at this time.
If however you mean a brief re-announcement (in case someone missed the first afk etc) then yes i see your point, sort of like server will go down in 5 minutes please find a safe area.
But then I think there already is (or did I dream that bit)
There have been cases where they did not announce the shut down of the server and just put a small normal chat line: server going down now and then you would be disconnected.
It's not always as elaborate as it should be...But most of the cases the announcements are repeated 3 times.
Well Erica server went down no announcement, stayed down 5 - 10 min 10 min afterwards mobs started appearing. I would be satisfied with a 2 - 3 min announcement. Sure if someone would pull the plug by mistake but still.
BTW on the tuesday maintenance or emergancy maintenance sure there are 3 announcement. But hell someone gotta know that the server is crashing, and give people a few seconds.
There is ussually a announcement about a half hour or so before the downtime is scheduled. They often send announcements every 5 minutes from 15 minutes and down. Unless the server were to crash of course then there is no way for a announcement.
Meh, I think we are used to it now, they have been having to do alot of maintenence lately. 4 hours compared to what we went through a few weeks ago, i'd take the 4 hours once a week ^_^