Supposedly it's too dangerous to be released.
NY Post article from 4/20: https://archive.is/8vQza
Metro Nashville Council Member Courtney Johnston confirmed to The Post the FBI has already ruled the manifesto would not be released any time soon.
“What I was told is, her manifesto was a blueprint on total destruction, and it was so, so detailed at the level of what she had planned,” she said, when reached by phone.
“That document in the wrong person’s hands would be astronomically dangerous,” she added.
Supposedly it's too dangerous to be released.
NY Post article from 4/20: https://archive.is/8vQza
If she was that level of strategic genius she would've accomplished more than shooting a few children.