When you do a search in Google News on "Boar's Head" the listed recent searches include queries about the stock price, about the plant locations, about the products and the distribution locations. Clearly some of those interested are the ones who eat it and others are interested in their investments.

In that Times article was the interesting information about how they tracked it down to Boar's Head:

The alarm rang after people like Günter Morgenstein, a hair stylist renowned in coastal Virginia, fell gravely ill. As Mr. Morgenstein, an active 88-year-old known as Garshon, grew frail in the hospital in early July, his family racked their brains to think of everything he had eaten in recent weeks.

As listeria illnesses spread, a disease detective in Maryland began to suspect liverwurst as the common thread, given the older age of the hospitalized patients. Her hunch proved correct: Whole genome sequencing matched the patients’ bacteria to Boar’s Head liverwurst bought at a store, according to the Centers for Disease Control and Prevention, setting off the recall of 3,500 tons of meat.

Liverwurst being a food favored by older people who have experience with it and still eat it. I've never had it.