Yes, it's true. After years of procrastinating, I'm finally working on The Evolving World Part 4 again.
I think what was stopping was the script I'd written for the episode. I'd written it a long time ago, and it lacked the dramatic weight I wanted from it. However, I've rewritten the ending completely, (and worked in a few cameos from characters in the comics!), and I think it's much better now.
This has motivated me to finally get around to it. Hopefully, it'll be able to come out next year. Maybe even on The Evolving World's five year anniversary. We'll see.