Because of poor research you have accepted an inaccurate translation of other bibles. They are woefully imprecise when they translate the Hebrew word OLAM as "forever."
Many lexicons and dictionaries would have shown you that OLAM’s DENOTATION is of an unknown length of time and NOT forever. It can be used of something that is to last forever but in itself the word can only *imply* eternity.
Witnesses accept the meaning of the word as given in standard Hebrew Lexicons. Here is what their reference work "Insight on the Scriptures" states:
"The Hebrew word 'oh lam carries the thought of indefinite or uncertain time. Lexicographer Gesenius defines it as meaning "hidden time, i.e. obscure and long, of which the beginning or end is uncertain or indefinite." (A Hebrew and English Lexicon of the OT, translated by E. Robinson, 1836, p. 746) Accordingly, expressions such as "time indefinite" (Ps 25:6), "indefinitely lasting" (Hab 3:6), "of old" (Ge 6:4), "a long time ago," "of long ago" (Jos 24:2; Pr 22:28; 23:10), and "long-lasting" (Ec 12:5) appropriately convey the thought of the original-language term. The word 'oh lam is at times associated with that which is everlasting...However, the Hebrew expression 'oh lam does not in itself mean "forever." It often refers to things that have an end, but the period of such things' existence can be said to be ‘to time indefinite' because the time of their end is not then specified."--it-2 pp. 1102-1103
The context and other parallel texts must be referred to in order to determine whether the sense of OLAM is to be understood as eternity or just an indefinitely long period of time in any specific occurrence.
The Witnesses do not use their teachings to interpret the Word of God, but rather they adjust and base their teaching on God's Word. They allow the Bible to interpret itself by using rules of exegesis including standard word definitions, Hebrew grammar and the senses of words as proved by their usage in the Scriptures.
On the other hand, you misinterpret this verse due to a theological presupposition.
According to the God's Word He rejected natural Israel and brought into being a "Spiritual" Israel made up of Jew and Gentile. This "Israel of God" was now the focus of the Abrahamic Covenant and all other prophecies restoration prophecies (Mt.21:42-43; 23:37,38).
Gal 3:29 says the "seed of Abraham" are made up of all nations who belong to Christ not fleshly Israel (Gal 3:16,29; 6:15,16; Rm 2:28,29; 9:24-27; Eph 2:11-16; Hos 2:23; 1Cor.10:18). Only a few Natural Jews would be saved--a "remnant." Paul only held out a hope to "save some from among them" (Rm.9:27; 11:5-14; Isa 10:21, 22).
John's vision of those on the heavenly Mount Zion revealed the spiritual Israel of God to be 144,000 "bought from among mankind" not "from among the Jews" (Rev.7:4; 14:1,4; 5:9,10; Jas 1:1).
In regards to Ezekiel your interpretation is convoluted and contradictory. You mix symbolism with literal as it suits your personal interpretation. For example you recognize that that "David" is not really "David" but is a symbol or "type" of Christ. But, then you insist that "land" is not a symbol but must be the literal land of Israel. This is a dishonest and illogical method of interpretation. If you accept that "David" is not literal but can be used as a "type" or figure for Christ in this prophecy then you also must accept "land" does not have to be literal and can be a type or figure for the domain of spiritual Israel i.e. the Christian Congregation.
The correct interpretation by Witnesses does not confuse and mix the literal with the symbolic. They follow the interpretation of Christ and the Apostles in applying the restoration prophecies to the spiritual Israel as the antitypical "land."
What proves that this prophecy of Ezekiel finds its greater and complete fulfillment in spiritual Israel is the clear and irrefutable teaching of the New Testament. The NT provides absolutely no fulfillment of these prophecies in the natural Jews or the literal land of Israel but it is always applied to a spiritual "Israel" (Rm.2:28-29; 9:6-9).
Your interpreting these prophecies as having a fulfillment on the literal Israelites or natural Jews is in complete contradiction to all the explicit Scriptural teachings which show that God has rejected natural Israel.
The only way to maintain your interpretation is to completely ignore all the explicit statement in God's Word that He is NOT using natural Israel.
So your interpretations must be rejected.
The restoration prophecies of Ezekiel are referring to the complete restoration of True Worship that would come at the "time of the end" (Ac.3:20- 21; 20:29-30; Lk.19:11,12; Mt.25:21-30; 2Thes.2:3-12; 1Tim.4:1; 2Pt.2:1-3).