It's not much, but it's always exciting to shout "land ho!" as you approach a new shore. There are two other shores that other spacecraft are approaching right now. OSIRIS-REx should first spot its target asteroid Bennu in August. It's possible that New Horizons will also first spot 2014 MU69 in August, but it is more likely to be September.

There's a specific reason that the Hayabusa2 images were taken now. The spacecraft needs to keep its solar panels oriented at the Sun for power generation, and mission controllers did not want to make major shifts to that orientation. The cameras are pointed exactly in the opposite direction. So the perfect time to try to image Ryugu would be if the spacecraft passed between the Sun and Ryugu, which it did on February 26. They found the asteroid precisely where they expected it to be, which is always good news!