I want the same thing as you do, but not in that way.
I am extremely disappointed from Mists of Pandaria, but i disagree, let's be serious, closing Cataclysm server? You realize that they spent much time working on it right? Mists of Pandaria too, they have spent time working on them, and loosing these 3000 players on Frostwolf and 1500-2000 players on Neltharion is not really helping them to become any more popular. For god's sake they are keeping Warsong running only because of these 150 players that are still playing there.
Warmane is known by it's success on Lordaeron, but closing Mists of Pandaria & Cataclysm servers, loosing these 4500+ players? that's not helping the community to become bigger at all, and it's a great risk to take, you are basically saying, remove these 4500 players from the game, and you will earn 10,000 new players. What if they replace Mists of Pandaria & Cataclysm servers with TBC & Vanilla and they have like 500-1000 players online? - Completely loss and waste of time.
There is only one way for this server to become more popular and bigger, that way is to keep working on what they have NOW
I know that development is expensive, keeping the servers running is expensive, website is on paid hosting, that's expensive too. I know this stuff.
The only way this server to grow even more is to hire/change staff members, new developers, more people that may have access to Warmane's changelog page, so changelog can never be late, and be posted right on time. More expanding and fixing, more designing, listening to the community. And eventually, if there is enough money, they may open a TBC or Vanilla realm, just for the hope of gaining new players. I am not hating, this is the wrong way.
They should not remove any expansion.
Wish you all the best.