The Septuagint was Greek. I don’t think the language was the problem, and thei is the first I’ve heard that books were excluded from the Bible because they were in Greek.
The Jewish Bible is in Hebrew, all of it. I’m not sure about the Talmud, but it’s possible that the Gemara was in Aramaic. I think it was written in Babylonia, and at any rate, when it was composed, Aramaic was the dominant language of the middle east.
Some the Jewish mystical tracts were in Aramaic, the Zohar, for one, and the Ketubah, the marriage contract, is in Aramaic, as is all but the last verse of the mourners’ prayer.
What I’ve read was anything not originally in Hebrew was excluded. Whether that means some books in the Septuagint were originally written in Greek or originally written in something other than Greek and only still existed in Greek I’m not sure.