Don't be a fool, walaal; the ancient Arabs or prophets never referred to it as Ethiopia, but rather as Aksum or Abyssinia. Furthermore, the entire horn was simply referred to as greater Abyssinia or Cush. That hadith, in reality, proves and explains why the horn of Africa has never been under any Islamic caliphate or empire, and why the ancient Arabs did not conduct campaigns in the horn like they done for Persians and Romans.
And they do not have some sort of heavenly decree because Somalis have physically invaded and conquered current Ethiopian regions for more years than I can count on my fingers and most have been successful, or else how was Islam disseminated into the depths of Ethiopia it was done by campaigns launched by Somalis. And that hadith is not for quarrels among fellow horners, but for who the initial Arabs were intended to conquer or take spoils of, with only the Romans and Persians falling as a miracle and prophecy fulfilled.