It seems odd that China would not have made a similar move already given its international clout in other non-maritime regards. So this can be read as China merely becoming a "stakeholder" in international affairs, finally assuming its rightful burden and duty as a rising major power.
It's also in China's self interest as a sovereign nation - with an economy fueled heavily by exports, it needs global shipping to continue to provide a safe, reliable means of transport. And significant Chinese economic investment and mineral resource extraction is underway in Africa - in places like Sudan.
Still, in the end, this mission, even if a minor one, should also be read for its symbolic significance - a first step in challenging U.S. naval predominance worldwide. While China has focused primarily on its submarine forces in the past decade by most indications, this is a different matter. It's about projecting surface power far from Chinese shores.