List of major WT revisions copied from https://beroeans.net/2022/11/26/a-bible-student-writes-to-her-jw-teacher/
(a) November 1881 – The slave is a class of individuals and refers to all anointed Bible students, Zions Watch Tower October and November 1881.
(b) December 1896 – The slave is one individual and refers solely to Charles Taze Russell.
(c) February 1927 – The slave refers to an individual and two distinct classes Jesus Christ alone, Jesus Christ and anointed Bible students.
(d) August 1950 – The slave refers to anointed Jehovah’s witnesses who make up the 144,000.
(e) December 1951 – The slave is anointed Jehovah’s Witnesses who make up 144,000 and is led by Watch Tower Bible and Tract Society.
(f) November 1956 – The slave is anointed Jehovah’s Witnesses under the direction and authority of the Governing Body of the Watch Tower Bible and Track Society.
(g) June 2009 – The slave refers only to the Governing Body of Jehovah’s Witnesses.
(h) July 2013 – It is clearly defined that the slave is the Governing Body of the Jehovah’s Witnesses only. This occurred after the large lawsuit in Australia when over 1000 child sex abuse cases, which prohibited suing the organization.
I found a good explanation of the faithful and discreet slave at https://beroeans.net/2020/05/15/examining-matthew-24-part-12-the-faithful-and-discreet-slave/