Speaking from the viewpoint of a Jew, I can attest to the fact that Watchtower ideas about the Bible canon show intellectual immaturity and limited, two-dimensional reasoning.
The idea of "canonization" is a Christian one, not something that comes from us Jews. The Roman Catholic Church had to develop a "rule" for what books were approved for Christians after a bishop, Marcion of Sinope, claimed that the Gnostics were correct about some of their ideas. Claiming that holy writings held secret knowledge that only a select group could understand, Marcion endorsed the Gnostic technique of creating lists of "proof texts" upon which to support his doctrine.
Rejecting all of the Hebrew texts, Marcion claimed that only an edited version of Luke's gospel and some of Paul's epistles were to be used as the "rule" or "canon" upon which to base all that was "true." The Christian church expelled Marcion as a result, but the genie was out of the bottle. They would spend the next 300 years investigating and answering the challenges raised by Marcion, eventually creating an "authorized canon" by the 4th century which included not just the 27 books of the New Testament but the particular list of books unique to the Alexandrine Septuagint (which is where the "additional" books come from), thus making a list slightly longer than what is found in the Tanakh.
This process never actually occurred in Judaism as the Marcion question was limited to what had become mostly a Gentile religion. By the 2nd century Jews had divided their religious texts by language and era, but this was never canonization in the Christian definition of the word.
Limiting their reasoning to the Christian definitions of "inspiration" and "canon," too many Christians are still making the mistake of claiming that we Jews have somehow rejected such books as Maccabees or the Wisdom of Solomon, etc. as found in some of the Orthodox and Catholic canons. Unlike many Christians who believe that religion is based on Scripture, Judaism is very different. Scripture is a product of Jewish worship, not its basis.
While some so-called "Catholic books" are not included in the Tanakh, Christians keep making the mistake that this means they have been rejected. This is just the result of ignorance. The Tanakh or Old Testament is limited to those books believed to be originally penned in Hebrew and during the era of the First Temple. The Alexandrine books were originally composed in Greek (with a few sections in Aramaic or Hebrew) and are of the era of the Second Temple, thus disqualifying for inclusion in the Tanakh on the basis of language and era of composition.
And Jews do not hold to the idea behind "inspiration" that Christians do regarding the Scriptures. The religion of the Jews itself is inspired, therefore its religious texts being a product of Judaism are sacred. So those books which get divided into categories such as apocrypha or Mishnah or writings which make up the Talmud are not excluded from the Tanakh due to "lack of inspiration." In fact many Jews commonly read the Maccabean texts every year during Chanukkah and have been doing so throughout history, so arguments made by many Christians with claims of trying to "be like the Jews" in accepting or rejecting certain texts are just nonsense.
The book of Enoch is not part of any official library of Jewish books because it is what we call "midrash." It is traditional analysis or commentary on parts of Torah, and since it is a commentary about books in the Tanakh it iwould not itself be part of that which it interprets. It was not "removed" from anything. Christians don't make commentaries part of their canons either.