As usual, the headline distorts actual meaning.
Note this sentence in article:
The consistency of results from session to session showed that soloists could definitely distinguish one violin from another.
So what the test showed was not that they couldn't distinguish the instruments one from another, but that in a blind test they didn't necessarily prefer the old instruments and didn't know which instrument was old/new.
In other words, if the test was valid, it shows they can tell instruments apart; but that preference for a particular instrument may be strongly influenced by "brand". Not the same as what some are trying to take the test to mean - that differences between instruments can't be heard.
I think it may very well be true that modern instruments sound better than the old Italian ones, but more testing would need to be done to back up this study. I even read about some professionals using a modern Japanese violin made of graphite resins, and they claim it is the best sounding instrument around, for a fraction of the cost of some of those 7 figure babies.
BTW, I've corresponded thru a forum with a professional violinist who wrote that picking a violin is very difficult. What the violinist hears when playing it is totally different than what the audience hears. He said his violin doesn't sound that good to him on stage, but very good to him when he hears it sitting in the audience, or when a recording is played back to him and he is listening as an audience would.
edit: the link above gives some perspective on why the test may not be what it is being made out to be, and why the methodology may have been flawed - at least as far as determining whether violinists actually prefer the sound of an old Italian violin.