No, I won't leave the origins of the city aside because it's founded and established by Somalis. It's part and parcel of their history and civilization. The newbies can't claim this ancient city and its civilization as their own.

I don't believe 138 years can qualify for identity or ethnicity formation unless it's politically motivated, which it's. Menelik II has used these same "Hararis" to conquer Harar and genocide original inhabitants - Somalis. 

The language is a fusion of Gurage, Sidamo, Afan Oromo, and some Arabic loan words. The appropriated culture is from Harar Somali civilization culture they claimed as their own.