Me thinks "A Watcher" is simply trying to arrest your attention.
Me also thinks that "A Watcher" is not very capable in his reading of English. The NWT repeatedly says (in Rev 7:4-8) that the 144,00/12,000 are "out of" (Greek ek) "the tribes of Israel"/"[each] tribe"
This follows the pattern of "the great crowd" who are "out of" the nations/tribes/peoples/tongues. This also follows the pattern in Rev 5:10, where 'persons are bought for God' "out of" every tribe/nation/ tongue/etc and made into a kingdom of priests.
The group that is taken "out of" is necessarily smaller than the group they came "out of."
I also think "A Watcher" is not as familiar with his Bible as he imagines he is. He appears to have forgotten that originally, the priests of the nation of Israel were to be taken from the firstborn of every tribe. In lieu of that, Jehovah instead took the whole tribe of Levi in place of every firstborn. What Revelation shows is a return to the arrangement as it was to be originally: The priests taken "out of" each tribe.
Understanding it this way harmonizes with the fact that the 144,000 are referred to as "firstfruits" in Rev 14:5. (See also Jas 1:18)
They're being "firstfruits" harmonizes with the fact that the harvest mentioned in Rev 14:15 is a grain harvest, not a grape harvest, a fact that the WT Revelation Climax book tries to artfully hide in its lying picture on page 213. The WT does this deception because they only want the 144,000 to be the "wheat" of the 'wheat and weeds' parable in Matthew 13.
It also harmonizes with Hebrews 12:23 which refers to "the congregation of the firstborn who have been enrolled in the heavens."
Understanding it this way harmonizes with what Paul said about the Israel of God in Gal 6:6, that it includes, "all those who will walk orderly by this rule of conduct," namely, those who accept the torture stake of Christ. (Gal 6:12-15) Which Jesus equated with being one of his disciples. (Matt 16:24)
Understanding it this way harmonizes with the fact that those who judge with Jesus, judge "the twelve tribes of Israel." (Matt 19:28)
To say that only the 144,000 make up 'spiritual Israel' requires that you explain away all these other references.
But if you accept that the 144,000 (symbolic or not), are drawn from a larger "nation," then, you merely have to accept these other references as they are written.
The GB, who persist in teaching the lies that "A Watcher" is regurgitating, are exactly like the older brother in the parable of the prodigal son, who demands that his younger brother not be accepted back not into the family. (Luke 15:25-32)
They are also like the "wicked" early workers in the parable of Matthew 20:8-16 who can't stand the idea of the later workers getting paid the same.
And more and more they show themselves to have the same attitude as Shebna did. (See Isa 22:15-18)