Ethiopian Airlines is trying very hard to be Africa's number one airline. They are investing big in both passenger and freight operations and generally speaking do an OK job.
Passengers have been waiting for this as up till now most mid-haul busy routes have been served by ancient 767s. They have a few 777 ER that are new but they desperately needed their 787s. Typical of Ethiopian to be first to fly the "fixed" 787 just for publicity.