Wormwood however is a trickier process to use to make alcohol from.
I would venture to say that nary a person in the world can make alcohol from wormwood. It is a flavoring ingredient only. To make alcohol from it would require the conversion of the cellulose into a carbohydrate fermentable into alcohol. I doubt the leaves and flowers of A. absinthium have enough carbohydrate/sugar to be directly fermented into any sort of alcohol. I suspect this comment was simply a slip of the tongue. A sort of verbal typographic error.
I will defer to others more knowledgeable than myself, but since absinthe was produced continuously through the 20th century in Spain and other countries while banned in other parts of Europe, it certainly wasn't "rediscovered" in the the 1990s. It was "re-marketed" in the 1990s. I suspect there are a few of the "clandestine" distillers in Switzerland who produced absinthe throughout much of the same period (though it was apparently not openly available as a commercial product) who would contend they helped keep the historical process alive.
Of the historical recipes I've read (including scanned images of the originally published books), all of the recipes prominently featured anise. It would seem to me that anise, next to the lesser relative quantity of wormwood, is a key ingredient and should be obvious in the taste.
I am likewise ignorant of exactly when the water dilution/louche effect became part of the historical approach to consuming absinthe, but since the flavor is so significantly enhanced by this dilution with water, I suspect it was part of the appreciation of this high proof liquor from its inception. To my understanding, it is almost a given that a product that doesn't have an appreciable louche effect does not contain enough of the key/historical ingredients to meet the definition of "absinthe". Otherwise, such products should probably be called "wormwood flavored" liquors.