Instead of comparing to Roy/Elm, which I have never heard of (has anyone?), he should compare it to livescript, a fork of coffeescript that has quite a few syntactic similarity to Haskell (it's inspired by it).
Roy and Elm are new languages that people who follow Haskell are probably familiar with. Comparing to them makes more sense than comparing to LiveScript if your audience is Haskell programmers.
LiveScript is not really anything like Haskell at all except in some entirely superficial ways. Even the syntax isn't all that similar. Essentially, it's a slightly more functional CoffeeScript. While certainly interesting to the same people and for the same reasons as CoffeeScript, it's not very interesting to people who primarily use Haskell.
LiveScript is a good comparison only in the way it transforms and is part of the wave of "compiling to JavaScript". For that reason it might be nice for me to mention it on the page.
Granted that LiveScript isn't Haskell, how are the syntactic features that are derived from Haskell not at all like Haskell?
The vast majority of the syntax seems based on CoffeeScript.
The defining characteristics of Haskell (to me, bear in mind I'm a Haskell noob) are strong, static, inferred types, and an emphasis on pure or near-pure functional programming (limiting side effects as much as possible). The defining characteristics are not a standard library function named "fold" or "takeWhile".
LiveScript has JavaScript semantics, like CoffeeScript. These semantics differ from Haskell in deep and fundamental ways. Yes, it might also encourage functional programming, but so does Scheme and Clojure, both of which are really nothing like Haskell either. I don't think this is controversial.
It borrowed some syntax, but from what I can tell, it's much closer semantically to Scheme.