I would assume it's merely to make sure that at some point you see Google News again, if only to close the tab that remained open.

I'm divided on this practice, especially on sites like Google News. On the one hand, if I read Google News, this is probably how I'd read stories anyway. I'd open new tabs for all the stories I'd want to read, close the Google News tab, and go about my reading.

On the other hand, I'm a fan of choice, and all but the novice web surfer knows the tricks like Ctrl-click and middle-clicking to open new tabs, which would open the stories behind the current tab instead of in front of like it works now...