This is just my take as someone who has developed customs stories for TDD and is currently working on one for Rebirth. If a big youtube were to pick up Rebirth custom stories I wouldn't be surprised if people start flocking to make custom stories. With all that said the new engine is much more powerful than the previous one and you can do so much that wasn't previously possible in TDD. The developers did not provide the greatest documentation on the code for Rebirth custom stories and to add more to the pot, the scripting for stories is a bit more complicated than TDD.
It takes time for these custom stories to be created but in combination with that Rebirth does not have the popularity that TDD had. Late to this post but I found it while searching for something on google but I thought I'd give my take on this.
