well still no answer?
The Infinity Ward team is celebrating their game launch with cupcakes e.g. as seen on twitter avoiding the fact that they still have a lot of work to do. They released an unfinished game, to put it simply.
Thanks for taking the time to post. I can assure you that the cupcakes have been consumed, so rest assured that is no longer a distraction.
Now, the official requirements for the PC version of the game is 6gb. For more information the requirements take a look here: http://community.callofduty.com/community/call_of_duty/english/ghosts/blog/2013/ 10/23/call-of-duty-ghosts-pc-system-requirements#.Unkjxvl4xMA
At this time I have no information on any changes, but I will be sure to forward up your suggestion accordingly.
6GB was stated in the requirements long before the game was released. I don't think they will/should be obligated to release a statement on this particular matter. Same goes for the DirectX11 and x64 bit OS stated requirements.
You should try checking out www.newegg.com. They usually have some good deals on memory and memory is actually fairly cheap nowadays.