That was paired with Gunbuster, and Gainax put out a call for people to work on a new project. They didn't do that with the Diebuster movie. If you put out calls for people to work on your project, it's not a compilation.
This is an original project. Period. It's one thing to be a cynic, but you should use logic.
Screencap this post just so you can rub it in my face if I'm wrong. "It will not be a recap movie."