I think the only path - unlikely but not impossible for the true film believer, as I am - is that film photography, and slide film in particular, begins a come back that will lead it, let's say in 10 years, to the levels of sales which existed during the first years of the digital revolution, when film sales were shrinking but not yet really in danger. For Europe that might mean something like 2006. For the US maybe something like 2003.
If and when film sales go back to that level, Kodak (or whoever purchased the technology using it with whichever brand name) might easily think about producing Kodachrome again. In 2006 Kodachrome was still a viable product and it would be some sort of a "flagship" product for Kodak, a bit like Porsche continues to sell their 911-family cars: even though they are not the latest in technology, there still is a market for "retro" technology provided it is well realized. Values like "tradition" and "history" do have a meaning, and Kodachrome might be the 911 (or the Morgan) of the future slide market.
The first condition to become true is that the market bounces back to where it was some 6 years ago. Not easy for sure, but not impossible either.
I think it would be easier to modify an E6 emulsion to give a Kodachrome like colour response and grain then to start making true Kodachrome film again. Would probably still cost millions to produce the first roll though.