I do live in a place where black ice occurs frequently. I also think most people driving around here are aware of the temperature and, with any experience, the driving conditions in that weather.
There are of course places where black ice occurs far more frequently that elsewhere, and yes, maybe in those places paint on the road surface could be more noticeable than a simple warning sign.
There was a corner near where my parent's live, which would form black ice very regularly. I would shout "black ice!" to people approaching by bike / motorbike when going to school, but almost everyone not aware of the tendency on that curve would wipe out anyway. Cars would skid until they found traction. A dangerous place to be walking around at times of the year.
For this to be (cost-)effective the places where black ice forms regularly would need to be recognized, cataloged and then painted on a regular schedule. Should this happen, then maybe this could be workable. Too many places with paint and it would offer no benefit since it would just be ignored, and most of the time a better solution would be to renovate those places such that black ice shouldn't form there anyway. As the paint was depicted in the article, as a continuous sea of snowflakes, it would only serve as a distraction making the road surface "too busy", possibly just distracting enough that you wouldn't notice something you really should have (like a kid walking to school.)
Freezing rain as a cause for black ice causes it to be everywhere and I think anyone traveling on a continuous sheet of ice is pretty much aware of it.
There might be a point for a application of the paint in some places where you cannot engineer black ice from forming, but as a ubiquitous road surface temperature gauge, not so much.