That's not really what the article is about: "Patients whose primary visual cortex was destroyed can still imagine, so the old idea of imagination as reversed seeing fails."

It's been "known about" but mostly ignored in research until recently, and most people who know about their aphantasia probably learned about it in the last 10 years because it was extremely obscure.

There reason it is being talked about now is exactly that so many of us learnt about it from a study in 2015 and the subsequent interest.

Knowing a thing exists is not the same as knowing how it interacts with other things.