"A few anointed members of "the Israel of God" still remain...
= The "Remnant"
...and as Jesus' brothers, they continue to act as "ambassadors substituting for Christ (2 Cor 5:20)
Nothing new
They have been appointed as a faithful and discreet slave class to care for and provide spiritual food for annointed ones and a growing crowd of Christians, who now include millions having the hope of living on earth forever. ...
It's been taught for at least forty years that the anointed alive on Earth at any given time are as a class, the "Faithful and Discreet Slave," but as individuals are also domestics that are fed by the Slave. To me this comes across as a repetition of that idea. (i.e. Contrast between "Class" and "Ones" (Individuals))