I think the article expresses no position. Most source code for array languages is not, in fact, inspired by APL. I encourage you to check a few random entries at [0]; Kap and April are some particularly wordy implementations, and even A+ mostly consists of code by programmers other than Whitney, with a variety of styles.
I do agree that Whitney was inspired to some extent by APL conventions (not exclusively; he was quite a Lisp fan and that's the source of his indentation style when he writes multi-line functions, e.g. in [1]). The original comment was not just a summary of this claim but more like an elaboration, and began with the much stronger statement "The way to understand Arthur Whitney's C code is to first learn APL", which I moderately disagree with.
[0] https://aplwiki.com/wiki/List_of_open-source_array_languages
I unfortunately glossed over the part of the original comment that gives it substance: "The most obvious of the typographic stylings--the lack of spaces, single-character names, and functions on a single line--are how he writes APL too."
That's backing for a claim.
Also, I haven't once written APL. I think this might've been borderline trolling, just because of how little investment I have in the topic in reality. Sorry.