The whole "slave class" is total bullshit.
I'm fascinated by the JW's choice of the word of "slave" over the word "servant." A slave usually has no agency and is owned. A servant generally has more agency and responsibility than a slave. In fact, the NWT is the only bible translation that uses the word slave that I know of. Also, slaves also don't generally fly Business Class but are generally chained in the cargo hold!
Based on my reading, the Lord encourages us to think of Him as our Father and us as His Children, and John says that "when we see Him, we shall be like Him, for we shall see Him as He is." (1 John 3:2) Certainly they will see this as the 144,000 John-class individuals, but still, this is hardly slave status!
In the past, the GB have said they're not leaders of the Society; they simply serve as a conduit of Jehovah's will. From God's mouth to their ears!