waton : Who exactly will fill that vacuum? Or is that to heavenly universal office?
Yes, those who make up the faithful slave will get their appointment "over all his belongings" when they
are resurrected to heavenly life during the great tribulation and given royal authority in heaven and on earth.
Jerryh : This is truncated but is it accurate?
As you noted earlier, in 2012/13 there was an adjustment in understanding. So your summary is out of date. Jesus' appointment of the "faithful and discreet slave" did not happen at Pentecost or in 1879.
The first inspection occurred between 1914 and early 1919, and the appointment of the slave over his domestics was in 1919.
At
that time the slave consisted of a small group of anointed
brothers serving at
world headquarters who were directly involved
in preparing and dispensing spiritual food.
In recent years, that group
has been identified with the Governing Body of Jehovah’s
Witnesses.
The second inspection is during the great tribulation when those who make up the slave will receive their
heavenly reward, becoming corulers with Christ. They will be sharing
this reward with all the anointed who have a heavenly resurrection.
If you want to read further on it, it is discussed in the 2012 Annual Meeting Report and The Watchtower of July 2013.