a simple request asking for GOG to add a CD Key to the original vanilla game, so that some of the issues people are having with it can atleast be ignored, since they would be able to simply use the Taleworlds version instead.

A serial key is a form of DRM. Every single player game here doesn't need a serial key.
I won't be surprised if GOG cannot help you.

Sure it's been five years but GOG only released the game about a month ago so how do you know that they're completely unaware of the existence of said patch and won't pick up on it? They might be in talks with TaleWorlds about releasing a version without the CD key requirement (for the very reason stated by Sarhento).
And if you firmly believe it's all due to ignorance on their part then why don't you simply enlighten them instead of spewing bile here?
You know, they might actually listen if you leave out the venom. :)

Or to compound my comrades point. Go buy it from Talesworld. Instead of complaining that you can't get what you want here. It makes logical sense to me to buy it from there if you want a patch thats not here.

Did anyone ever contact Support about this?

I'm curious if it works like UT2004 did: contact GOG, get a unique key. It was because the servers tend to reject you due to the one every game was originally packaged with.

I'm playing mine just fine. Also playing SW Conquest 0.9.0.3 on MB 1.011. No need to call people names.

Such language.

To OP: If you need to get past the Serial check I've heard you can do it using Warband's serial if you own it, or then go fishing in the internet for it.

Hope this helps. If not...

GET WARBAND YE PEASANT! :)