Did you read the paper or are you just spouting off about the most obvious possible issue and assume that people who write and review papers on this subject for a living didn't think of it?
When whole colors didn't even have names several thousand years ago, things can be dubious (e.g. wine-dark sea).
This is part of peer-review -- being able to defend the ideas. When the academic "peer" group is reduced to "only those from certain institutions and pedigrees" it really waters down the quality of peer review. Go back 250 years, and peer review was your buddy you met at a symposium two countries over, because only a handful of folks had general interest (i.e. no Quanta magazine yet).
If the exposition of those ideas are locked behind a paywall from peers with interest, then it really isn't very peer reviewable.
I too do not have institutional access.
I have often wondered about that one - is it due to light intensity at Mediterranean latitudes, or the frequency of storms, or the predominance of bronze at the time? Or was there a greater variety of grapes and wine colors? Or is it to do with the absence of glass, so that colors were appraised as they appeared in metallic drinking vessels?
Linguistic drift can occur due to contact with other cultures, changing environmental conditions, availability of new dyes, or political factors. As an example of the latter, consider an absolute monarch with a color vision deviation from the biological norm. Their opinions about colors could become the 'official' one, and over a long reign this could become institutionalized. Chinese culture, for example, identifies 5 fundamental colors and they're invested with far more symbolic specificity than in western societies: https://en.wikipedia.org/wiki/Color_in_Chinese_culture
And I'm not trying to be dismissive of the paper. I just have some doubts because it needs to pile methodological inferences on top of each other over a wide variation in both space and time. If you throw lots of different circles on a Venn diagram and they all have a pretty consistent overlap, then yes, that probably means something. It's a worthwhile approach.
But the fuzzier the boundaries, the harder that task becomes. I'm happy to buy into the idea that Betelgeuse changed color relatively recently and people noticed: my point was to list some confounding factors that make pinning that down very challenging.