"(1200) web sites around the world. Those sites have agreed to conceal the information until such time as contact with Snowden is “lost.” Once contact is lost, "
do you really think that 1200 sites will not publish this before ? no way!
The file would be encrypted with the password to be released upon mishap. The 'web sites' would conceal the fact that they had the file and ability to publish the data if unencrypted.
This seems inherently less robust to me than just distributing the encrypted file in advance to everyone who wants it (along with a checksum of course) as did Assange. Web site operators could be put under considerable threat, and it would be possible to severely criminalize the act of disseminating or obtaining this data in raw form as well as to carefully monitor and record exactly where the data flowed.
Assange's data is sitting on thousands of thumb drives waiting to be read (if there is anything there at all.) Even the global internet itself is not especially necessary to get at the data.
That Assange-style was not the chosen method for promoting this threat leads me to believe that the story is probably bullshit.