Following Loctav's leave from osu! management at the end of 2017, the Quality Assurance Team (QAT) elected QAT leaders to take control of the group. This decision was made because members of the QAT felt that Loctav and Ephemeral had too much control of the group, and that the QAT would be better led by its own members.
The vote for QAT leaders was handled through a vote of all Beatmap Nominators and QAT members. Results of the vote, found here, promoted Okoratu and JBHyperion as the first QAT leaders. Their responsibility was to work with the osu! team to maintain the mapping and modding communities.
The QAT leaders were replaced with -Mo-, Mao, and Ascendance throughout the next two years.
By 2020, there was no need for a formal QAT (eventually Nomination Assessment Team (NAT)) leader position, which lead to it being discountinued.
As of March 2023, the NAT has decided to re-adopt the concept of leadership; for more information, see Nomination Assessment Team § NAT Leadership.