I mean, he was the last to be offically crowbed as emperor (as far as I know), and wasn't Ethiopia known as the "Ethiopian Empire" before the communist coup?
So, was he?
If you're asking for a leader who went by the name emperor and ruled after Selassie was deposed in 1974.
Jean-Bédel Bokassa declared himself emperor of the Central African Empire ('Empereur de Centrafrique par la volonté du peuple Centrafricain') in 1976 and was only overthrown 3 years later in 1979.
After him, there's japan. Which still has an Emperor. As of 2017, Akihito is still emperor of japan.
So no, basically.