From the article, 1998 was the year that the Tobacco Institute and the Committee for Tobacco Research disbanded, which I am perceiving as symbolic of the last formal resistance to the idea that smoking causes cancer.
Sure but it's a pretty arbitrary cutoff. Many other significant limits on smoking (workplace bans, indoor bans, airlines, etc) and various limits on tobacco advertising happened both earlier and later. Some big tobacco lawsuits happened later. Just about any doctor in the 70s, 80s or 90s would have told you smoking is bad for you, public perception and knowledge of the dangers changed over time, etc, etc, etc. The whole thing doesn't really fit in a neatly bracketed time period in a meaningful way.
