It depends on the meaning of the word. Agent Orange is both a chemical and a weapon, so yes, it's a "chemical weapon", but its primary purpose is killing trees, not people, and its health effects were largely an unintended consequence of a manufacturing side product, dioxin. Most people understand "chemical weapon" to mean weapons
intended to kill people, like mustard gas, sarin, VX, ec.
And yes, the original article definitely plays pretty fast and loose with scientific terminology to amp up the scare factor. A cup of coffee contains "likely carcinogens", mutagens and teratogens, the issue is the quantity and the likely effect.