the overall movement towards more restraint in CA
I think she just doesn't have a lot of experience and she's writing from the viewpoint that her own context and preferences imply some broader trend.
In 1990, average sugar content of CA wine grapes at harvest was approximately 21.4 brix and 20 years later it was 23.3, which implies a corresponding 9 percent increase in alcohol. Winemakers can fudge the numbers on the bottle, but the LCBO tests every bottle for the actual alcohol level and their numbers for alcohol correspond to the brix from 1980 thru 2010. You can get them on line.
Why did that happen?
Any number of reasons. Let's see - there was an enormous increase in vineyard acreage and the fact that many many vineyards were replanted in the 1990s because of phylloxera problems. That brought new rootstocks, trellising, densities, orientations, etc., all of which affect the final wine.
And an average increase in temperatures in many places. And a better understanding of how to eliminate green, unripe flavors.
But Zin was always rather hi-alcohol relative to say, Cab. Unless I'm mistaken, in the 1970s, Montevina and others were making Zins in the mid 14s, which was quite high for the day when Cabs were much lower.
In fact, Zin was always considered a hi-alcohol grape partly because the clusters ripen unevenly and maybe even more because it was so widely grown in warm regions to produce quantity jug wine. Even today, while it's a relatively distant second to Cab in acreage, it's very close in tons crushed for the same reason.
So I have no idea what "movement" she's talking about, except perhaps a handful of winemakers who have decided to make wine of one style vs another, which is something that's almost inevitable when you greatly increase the number of winemakers and available grapes in a state. It's not a trend, it's a natural example of multiple approaches from multiple individuals.
And looking at a bottle of 1983 Ridge Zin in the cellar, I see it clocks in at 12.0%, whereas a few random bottles from 1994 and 1994 and 2005 and 2007 and 2009 all come in around 14.5. So which is the "claret" style that they've "always" made?
For my 2 cts, she seems very nice and charming and like many people working in Brooklyn wine stores whose experience goes back maybe 10 years at most. I like many of those people very much. I just don't expect to learn a lot from them. But whatever blows your hair back.