[impendia]

> this looks to be more concerned with applications towards number theory (specifically cohen-lenstra heuristics) rather than adding to the category theory literature.

(I'm a specialist in this area of number theory)

This is correct. The word "category" is being used in its colloquial English sense; this is not work on category theory.

[Edit: I'm mistaken in the above point; see comment below]

[hgsgm]

It's weird. It definitely reads like the Quanta author either didn't know what a mathematical category is, or didn't think it merited explanation, despite explaining simpler things in excruciating detail in the article.

[eastWestMath]

The paper is absolutely a construction on categories.

[impendia]

Okay, looking at the paper more carefully (I'd just looked at the article before, and was arguing from my knowledge of the field more generally), I take it back -- there is definitely some formal category theory here.