I can't believe you watched the same piece that I did. Your thread title is accurate - indeed a few individuals that were already within the US aided the attackers. But that's hardly new information. And to say the redactions where a "Bush administration cover up" of "Saudi involvement" misrepresents the 60 Minutes piece. You clearly seem to be implicating the Saudis as a nation - a government decision - instead of the mere fact that actors involved are Saudi.
Yes, the 28 pages are about Saudi Arabia. The section of the report redacted by the Bush administration is about links to co-horts to the 9/11 attackers there were Saudi, and indeed at least one was a member of the Saudi government (a member of the LA consulate, and certainly not key or "senior" official). The 28 pages and those who now speak about them claim that this is not "official" Saudi involvement or even tacit Saudi (as in the Saudi government) involvement. And the 28 pages are also about aspects of the kind of Islam centered in Saudi Arabia that tends to fuel jihadism, and how that version of Islam is both nurtured in Saudi Arabia, and exported.
In other words, the 28 pages are fairly critical of what the Bush administration deemed to be an important ally in the Mid East . . . hence the redaction. But the 28 pages aren't about a smoking gun that links the attacks to the Saudi government as some kind of orchestrated attack.
You do your cause a disservice with mischaracterization. But I agree with you that there's no reason to keep it classified.