In the May 15, 2011, pg. 23 Public Edition Watchtower, in the article 'O the Depth of God's Wisdom', there is a small footnote that essentially does away with an entire 1983 study article worth of material regarding the meaning of the Olive Tree, spoken about by the apostle Paul:
(Romans 11:17,18 NWT) 17 However, if some of the branches were broken off but you, although being a wild olive, were grafted in among them and became a sharer of the olive’s root of fatness, 18 do not be exulting over the branches. If, though, you are exulting over them, it is not you that bear the root, but the root [bears] you.
The Watchtower explains the verses as follows:
13 The apostle Paul goes on to compare those who become part of Abraham’s seed to branches on a symbolic olive tree.* (Rom. 11:21) This cultivated olive tree represents the ful?llment of God’s purpose with regard to the Abrahamic covenant. The root of the tree is holy and represents Jehovah as the one who gives life to spiritual Israel. (Isa. 10:20; Rom. 11:16) The trunk represents Jesus as the primary part of Abraham’s seed. The branches collectively represent “the full number” of those included in the secondary part of Abraham’s seed.
15 ...Thus, spirit-anointed Christians of the nations, such as some in the congregation in Rome,were ?guratively grafted onto this symbolic olive tree. In this way they became part of Abraham’s seed. ...
The footnote states.
* Evidently, there is no typical or antitypical olive tree. Although natural Israel did produce kings and priests, the nation did not become a kingdom of priests. Kings in Israel were prevented by law from becoming priests. Therefore, natural Israel did not serve as a typical olive tree. Paul is illustrating how God’s purpose to produce “a kingdom of priests” is fulilled in connection with spiritual Israel. This updates what was published in the August 15, 1983, Watchtower, pages 14-19.
In the 1983 study article, it had established the type/antitype as follows:
ROOT (Abraham/Jehovah)
TRUNK (Isaac, Jacob, 12 Patriarchs / Messiah Jesus (primary seed))
BRANCHES (12 Tribes of Israel / 144,000 spiritual Israelites (secondary seed))
WHY make this change? It's usually apparent that teachings aren't usually changed unless there's a good reason to do so. For example, the reason for the change of the generation from "wicked" to "anointed", and the withdrawal of the 1935 sealing (likely influenced by the increasing numbers of anointed ones), became clear with the introduction of the "overlapping gneneration". The overlapping also helped to created a sense of urgency again (even if some still don't understand it). The clarification on allowable minor blood fractions brought some order to the patchwork of allowable fractions written about over the years.
But dropping a type/antitype? There are tons of those that they dig out from the past. Why this particular one?
Here is my theory, but I would like to hear yours as well:
Drawing a type/antitype parallel between the 144,000 spiritual Israelites to the Literal 12 tribes of Israel makes one notice that Israel has both priestly and non-priestly members. This could lead one to the conclusion that spiritual Israel could also have both priestly (anointed/144,000) and non-priestly members (great crowd or other) . This obviously conflcts with the JW teaching that spiritual Israel is made up exclusively of the 144,000 anointed ones. If I were to take a wild guess, I would think someone pointed this out to them, so they got rid of the parallel in order to reaffirm the belief that spiritual Israel is made up ONLY of the "anointed" ones.
That being said, it still doesn't attemp to explain why the 144,000 in Revelation are spoken of as having been sealed out of every tribe of the sons of Israel (suggesting that there are other members of "spiritual Israel" outside the 144,000 elite/kings/priests).
PS. Don't forget the reminder reminded in the following article, "Following Christ, the Perfect Leader", after introducing this change:
Yes, Jesus’ leadership is progressive, not stagnant. Another way to cooperate with Christ’s “brothers” is to have a positive attitude toward any re?nements in our understanding of Scriptural truths as published by “the faithful and discreet slave.” (p. 27)