Some notes about the authenticity of the document:
1. The signature "Thisisahll Maydeup" is crossed out in at least one of the versions of the documents, switched by a signature that seems to be by someone else. The Rushmore document is also signed by "Thisisahll Maydeup", which is then redacted and signed by Pernell. As far as I'm aware the Rushmore document is canon, so I don't think "Thisisahll Maydeup" disqualifies this document, just like it doesn't disqualifies the Rushmore document. You could then ask yourself why using "Thisisahll Maydeup" in the signature? Maybe because if the document was to leak into public hands, people would think it's fake because of that signature.
2. If you're looking for a good reason to make the document non-canon, besides no further evidence of the outbreak, it's the grammar mistakes. From what Coldstone and I managed to deduce, the document includes grammar mistakes such as "Labratory", "Unconcious". As mentioned in the original thread, these were ironed out in the final version.
In that case the document wasn't important enough for grammar review and therefore may not be important.
3. Going back to why it could be canon, if Treyarch wanted some dummy text they could use "Lorem ipsum", and in fact they have used it in Classified, but not with this document. Also there were quite a lot of versions of the document, so that could be a sign for it being canon.
If you ask me, I don't think Treyarch expected people to recover the the content of the document. However, one of the great things about zombies is how Treyarch listens to the community and adapts the storyline and the way it is presented accordingly. It may not affect the current storyline, but I like the idea of it being related to future story. Only time (travel) will tell. Great post.
