It was in 2000 so it was not relevant to the on-going investigation. It probably has more value to let it out to the media (if they dared broadcast it) so the public can see how her mind works.
Now a smart prosecutor could use it as background at trial as it goes to intent. But I’m sure there would be a challenge to that to stop it from being admitted into the record
ABC news put it briefly on its website and took it down because they did not get permission to use it. Some people know about it.