That doesn't say very much, actually...even IF it were true.

a "decision not to tell the truth about what happened." does not signify that they KNEW the whole 'truth'. It could mean that the vague phrase.."...some level of the government, at some point in time …" merely indicated an attempt to cover up "someone's" inefficiency or slow response. NOTHING in that phrase asserts or indicates any knowlege of or participation in planning the attacks...or even in any significant cover-up.

   You have to be VERY careful what you read into remarks that are (currently) inserted at the bottom of an article of an editable Wiki. If those sentences you quote were that significant AND true, at least one of the 23,217 conspiracy theorists would have done something more with it.....

What's that you say? You are going Googling to find out? Have fun...