Please see my comment and the thread at the time this was deprecated: https://support.khanacademy.org/hc/en-us/community/posts/360078571572-World-of-Math-How-can-we-replace-or-recreate-it-
Evan, I'm just catching up with this topic and saw your reply there (from 7 months ago). This looks like a related thread. I also see a few comments from people who might be brought together to help move this (MB, Kae). I would be interested in working on this with a group and developing a closer connection with the KA organization to support the effort.
Please feel free to contact me.