Apostasy as used in N.T Greek refers not to a person merely "standing apart" from her or his former Christian Faith, just ceasing activity with the congregation, it is the idea of withdrawing from communion with the church deliberately, and is more often associated with going to a new or former pagan belief in preference to the Christian one, including Idolatry of course.
I think the Org does in words, in its literature, draw a distinction between an inactive person, and someone embracing opposing beliefs to the Org. The problem is that in practice, even the merely inactive are treated by the Rank and File J.W's as though they are out and out Apostates. And the org. wants this to be so, even if the reasons for inactivity have nothing to do with Doctrine, but, as is more than likely, to do with the way the Org and its members work, "mistreating the flock" in many ways, that individual is as dangerous from the Org's point of view as someone like me who can demolish their house of cards that is their teaching, in a heartbeat.
So the Org. uses "apostate" as a demonising word, aimed at all who no longer actively support the org, to trigger certain behaviour in the faithful, that will ensure they remain entrapped in the Cult.