The author notes here (in the HN thread) that it's a very very cursory overview and there are plans to add more later given time. This could have been a blog post (or series of blog posts), so maybe the academic-paper feel was misleading.
While I'm not sure this content should be on the front page, it never was represented as a very deep comparison. I do admit that when I read it through I expected much more.
Also, how do you determine what libraries to use and what projects to invest in these days? Do you always do a full audit of every project? I know I don't have the time, so I use stars on a Github project just like one might use word-of-mouth. If a ton of people think a thing is useful, it's probably at least a little useful. Of course, that kind of thinking can be dangerous (see: javascript ecosystem), but a lot of the time, it's "good enough".
BTW, the paper does cover a tiny bit of information regarding differences in platform support when it covers how Swift deals with concurrency.