My guess is that is more likely to happen if you find the money to fund that development.  Do you have any suggestions of grants or other resources they could use for it?  Or are you proposing to pay them to develop it?

IMO, Khan Academy needs to focus on maintaining their existing math and other courses, which they are struggling to do with their current small staff.  Adding completely new subject areas seems like a bad idea to me until they are successfully able to make small but important corrections to existing video transcripts in less than 2 months.