The 4/15/88 WT says this.....
"11 God certainly realizes that carrying out his righteous laws about cutting off wrongdoers often involves and affects relatives. As mentioned above, when an Israelite wrongdoer was executed, no more family association was possible. In fact, if a son was a drunkard and a glutton, his parents were to bring him before the judges, and if he was unrepentant, the parents were to share in the just executing of him, ‘to clear away what is bad from the midst of Israel.’ (Deuteronomy 21:18-21) You can appreciate that this would not have been easy for them. Imagine, too, how the wrongdoer’s brothers, sisters, or grandparents felt. Yet, their putting loyalty to their righteous God before family affection could be lifesaving for them.
12 Recall the case of Korah, a leader in rebellion against God’s leadership through Moses. In his perfect justice, Jehovah saw that Korah had to die. But all loyal ones were advised: “Turn aside, please, from before the tents of these wicked men and do not touch anything that belongs to them, that you may not be swept away in all their sin.” Relatives who would not accept God’s warning died with the rebels. But some of Korah’s relatives wisely chose to be loyal to Jehovah, which saved their lives and led to future blessings.—Numbers 16:16-33; 26:9-11; 2 Chronicles 20:19.
The WT uses that line of reasoning that apostates would have been killed in bible times and those who go against their teachings are to be considered apostates and avoided as if not alive.
BUT let's further explore this, apostates are those who do not put faith in the GB. Even though they have insisted on dates and how long a generation is, and that we should take those teachings as coming from Jehovah himself, does Jehovah have anything to say about that?
He does, at Duet 18:20-22 - "However, the prophet who presumes to speak in my name a word that I have not commanded him to speak or who speaks in the name of other gods, that prophet must die. 21 And in case you should say in your heart: “How shall we know the word that Jehovah has not spoken?” 22 when the prophet speaks in the name of Jehovah and the word does not occur or come true, that is the word that Jehovah did not speak. With presumptuousness the prophet spoke it. You must not get frightened at him.’
So that is interesting, Jehovah didn't allow 'over eagerness' to be an excuse, if a prophet who presumed to speak in Jehovah's name, commanded those words be treated as coming from Jehovah himself, they were to die!!
So, before an 'apostate' could be considered an apostate because of not putting faith in the GB, the GB would have been executed prior to that one saying so called apostate things on not putting faith in them, hence they wouldn't even become an apostate.
I wonder how the the GB would respond to those facts?