The point of the article is that they've discovered a concrete physical link between environment and DNA. We knew it happened, but now we have an instance. It's a pretty big step.

Aside: Evolution works by natural selection across generations - the ones with the good genes live, bad genes lose. An individual's genes don't need to change for the process to take place. Of course, random mutations in DNA are a big part of what cause the variation that results in good and bad genes, so yes, sometimes changes happen within an individual. But those are random changes, whereas this is a response to the immediate environment.