Oh, it's definitely true that general public knowledge of Turing's life and work has increased over the years. I just don't think it has anything to do with those "key documents" that were released in 2012, as opposed to, you know, the movie about his life and the public apology/pardon he received around the same time.
He was born in 1912. There was a lot of celebration in 2012 relating to the 100th anniversary of his birth. Not just the 2014 movie.
Alan Turing's Google NGram certainly supports your impression that "general public knowledge of Turing's life and work has increased over the years."
Wasn't jgrahamc largely responsible for the apology?
Yes
That was an excellent campaign.
Neal Stephensons Cryptonomicon came out in 1999, which while fictional, features Turing and his work very heavily and was a popular book in America, so that doesn't seem totally correct either.