Parties or fronts are organised by ethnicity (except within the opposition). In this kind of arrangement positions are filled by ethnicity or shared by ethnic parties. For example, upto now PM position by TPLF, Speaker of parliament by OPDO, Deputy PM by SNNP etc... All powerful positions are divided by ethnicity. This power sharing arrangement can be fixed. So far we have seen changes in deputy PM position, first was ANDM representing Amhara now SNNP and the speaker of parliament also changed hands. Now some are looking for changes in PM position, may be changes in all high positions.
EPRDF has to choose 1. fixed 2. rotating every election or two. This is something the EPRDF have to discuss in the future.
Therefore there is nothing wrong if TPLF or TPLF generals say it should be TPLF forever, for now till end of term or up to next election or two.