Why would they downgrade monsters going into a sequel?

I'm pretty sure king Ghidorah is going to be the big bad of the series. Maybe introduced (or teased) in two, and carried over to three. They never confirmed all the monsters for 2, just that they will all eventually appear.

What we fans want and what Legendary "needs" to do or "should" do are two very different things dude. Your opinion is your opinion, but Legendary "shouldn't" do anything unless they know that it's going to work and have planned it out very carefully. Randomly naming a few of your favorite monsters is the polar opposite of that.

Anguirus would slide perfectly into those ranks already confirmed but as G-FAN said, it has to be meticulously planned and thought out so naming a random bunch of hopefuls isn't likely to get them into the films, I probably sound really mean but that's just my opinion.

The way i would put them in 3 is have one big final fight agenst Ghidorah with godzilla mothra rodan anguirus baragon and varan but thats my opion.

Considering what G14 originally started as years ago I wouldn't be surprised if Hedorah was the baddie for number 3. Even if you hated G vs. H you must admit with modern effects the potential is insane. For that film I would be content if it was just Hedorah.