Haven't you read Rise of the Lich King? The main Undercity page explicitly says the following12/09/2012 07:33 PMPosted by VyrinUndercity is Lordaeron despite it never really being referred to as such,
The Undercity was so named many years before the Forsaken claimed it as their own. Far beneath the palace of Lordaeron, the Undercity held the ancient crypts and catacombs of Lordaeron's royalty, as well as the city's dungeons and sewers. Although the Undercity was only intended for prisoners and the dead, the poorest of the Lordaeron people lived within. When the Alliance captured Orgrim Doomhammer, they sent him to the Undercity; sometime later he managed to escape and wandered for many years afterwards.
I believe that you need to get your head checked. It doesn't really matter if the Forsaken are related to Lordaeron or not, because they're still occupying the city anyways, and no amount of your insisting that they have any right to it is going to move them.12/09/2012 07:33 PMPosted by VyrinThe Forsaken are not Lordaeron and have absolutely no relation to Lordaeron. If you believe they do you need to get your head checked.
I'd just to ask though why is this such a touchy subject for you? I mean if you think about it the Forsaken are groups of rebel undead and the majority of them are human. While they may not be Lordaeron citizens they likely are from the Lordaeron continent. And considering that the Scourge completely obliterated Lordaeron you would expect a great deal of the Scourge to be comprised of them, and as a result the Forsaken to be comprised of them as well.