Good point - it should definitely be dismissed without any further explanation. What possible relevance could anything from 18 months ago have to today?

What? I never even implied anything like that. It just should be taken with a grain of salt, as quite a few points will be out of date (e.g., supported features, code size, …).

From the text: "uClibc 0.9.33.2 (Buildroot 2015.02)"

In all fairness, this can't be from mid-2014 if they used a library build from 2015.

So why are both musl and glibc from mid/early 2014, and dietlibc from 2009? That's an awful lot of cherry-picking versions with no stated justification.

I think it's because those are the freshest stable versions the author could use? uClibc 0.9.33.2 by itself was released in 2012. I guess he had a reason for using the BuildRoot 2015.2 version.