It is not meaningless if you are using the exact same wine in both tests as the author points out.
Unless you have specific reasons to suspect foul play, your probability would be very very near 1 (certainty). Now, overcoming this near-certainty with our poorest senses of all, taste and smell, is quite difficult.
The point is that the quality of the wine does not seem to be objective, and neither are the descriptors used (oaky flavour, etc.)
I mean, it is subjective in the same sense that the sky being blue is a subjective thing. In other words, a philosophical debate over qualia.
But if you ever had a wine-tasting dinner with a large company of people, with a ranked progression of wines, you would not doubt that certain qualities of wine are absolutely shared amongst almost everyone who drinks them.
I'm fairly confident I couldn't tell a merlot from a cabernet, blind, from a glass. But that doesn't mean one wine doesn't taste nicer than another, or goes better with a particular dish. And that's what I was alluding to.