How can I retrieve all my movies from Theater now that's it's been removed?

So Apple has gotten rid of theater, and I can no longer upload to this convenient feature for watching movies on my Apple TV. What happens to all my movies in Theater? I no longer have the iMovie files that I used to create the original movies on older machines.

How can I retrieve all my movies from Theater?

And why in is that Apple has decided to get rid of Theater, and totally screw everyone with a Theater library? Wonder what Google users would do if they took the same action with YouTube?