Article is wrong on a few things. There's way more than 3 novels.
And there is something that doesn't match up. They say they are going to base it on the novels to avoid previous entanglements when the first script was based on the first novel.
All the props made by WETA were pretty much H3 vintage though. That seems a much different timeline than the original script. It might be what they were referring to. Those article writers really need to articulate their facts better. It's like me saying "Jango Fett is based on Boba Fett, a popular Star Wars EU character." While those are facts, they are misleading in the way they are put together. It implies Boba is only an EU character, and fails to imply the more direct family connection between Jango and Boba.
You know what else is going to hang up development? They're going to make a game for the release, Halo:the Movie: the Game. It will be the first Halo shooter not made by Bungie.