"... but water has essentially been confirmed for years now. ..."
From the article, "... This is the first time we're actually seeing water-transported gravel on Mars. This is a transition from speculation about the size of streambed material to direct observation of it ..."
Yes, it is good foundational geology being reported upon.
What's cool about that is that it allows you to directly calculate how much water flow was involved in moving this gravel (taking in to account the much lower Martian gravity), you can use the pattern in which the gravel deposited itself to determine what direction the flow was going, and more.
From the article, "... This is the first time we're actually seeing water-transported gravel on Mars. This is a transition from speculation about the size of streambed material to direct observation of it ..."