JWs have it wrong. Remember, the "evil slave" represents the WTS. Thus there were 9 other slaves sent out. Plus Jesus says, "I have OTHER SHEEP not of this fold." So Christ gathers his faithful ones in more than one fold! JWs may be the chosen temple sect, but it is not the only means Jehovah selects those destined for life.
So basically, 1/3 of today's population will be destroyed at Armageddon. 1/3 will survive and live into old age and die. And 1/3 will be granted the special privilege of living to the end of the millennium.
But after that, after Satan is let loose and then destroyed, then JUDGMENT DAY comes and everybody comes back and is judged. Based on the 1/3 that rebelled of the angels up in heaven, I'm presuming a similar ratio of those who will choose Jehovah among humans. Thus every human has a 2 out of 3 chance of getting everlasting life. That's not that bad.
God wants the best for all. He only destroys those who disrupt the peace and prosperity of others.
LS