I think the presumption here is that they are white and reducing the look of dark spots and not someone with darker skin lightening it overall.

A challenge with skin-related literature (and internet comments) is that there's always the unspoken assumption that you're talking about a white person unless stated otherwise. Even the article reads oddly of you start off thinking of them as a dark skinned person.

Aging skin usually accumulates pigmentation abnormalities, like hyper- and hypopigmentation. Ascorbic acid might be able to help both. That’s not exclusive to Caucasian skin types btw.

In my case, I‘m just taking it as a sign that it’s working, as pigmentation is only one of the areas AA affects.

Lookup lipofuscin, many spots are made of it. Goes beyond aesthetics