"Re: the origin of the word Jehovah that was in the Aid book - why did WTS remove that important piece of history from the Insight book"?You mean that it was coined by some Catholic monk? I have no idea, I would have left it there.
Part of WTS' policy of both rewriting and obscuring their history.
Rutherford took a page out of his contemporary's "branding" strategy (Hitler - moustache, and swastika flag design).
Rutherford's masterpiece was grabbing the obscure, seldom-used word Jehovah, and definitively stating that this was God's name.
The next critical step was also a masterpiece - "Jehovah's organization."
"wait on Jehovah"
"leave it in Jehovah's hands"
"trust in Jehovah"
"rely on Jehovah"
Brilliant, and appalling.