If you want to get another castle put in your best chance is making a suggestion in the actual suggestion thread, not the general discussion thread.
I'm inclined to disagree with you though. We simply do not have enough active players in this game to justify another WoE 2.0 castle.
Also, as Boogieman said, WoE 2.0 is still in its beta stages. There could still be major changes in the future... so releasing another castle at this point could lead to more confusion for players and more work for the GM team later on.