If I’m skimming and understanding that second link correctly, Julia already has far stronger support for higher rank and higher kindred types than Haskell: Haskell requires a language extension to use Rank-N types, while Julia is designed around dispatching with them. (I apologize in advance for any misrepresentation, I’m making generalizations off of skimming just one blog post summary, which I know is generally a bad idea.)
Also see previous discussions at Function Parameter Speculation #17168 - #28 by StefanKarpinski