Well if it's the world's first short range rocket intercept, which I doubt, big whoop, we've proven we can detect and engage mortar shells with similar.
AFAIK, its not. A variety of systems have knocked down short range shells, bombs (the correct term for a mortar projectile btw
), and rockets including:
Centurion (phalanx ciws on ground instead of a ship) vs. a variety of targets
THEL experiment (and other directed energy systems) vs. short range artillery rockets
Hell, the brits have shot down a 4.5" shell with a seawolf missile before
Anyway, conventional CIWS and RAM (and the british/canadian goalkeeper) are all designed to hit ASCM's, which are not only non-ballistic, but travelling much faster than short range rockets and shells.
However, this may be the "first" if you narrow it to a
guided missile intercept of a
short range (<50km ) battlefield
artillery rocket in an
operational condition (not a test)