Well to be fair they had to confirm the anagram was correct because everyone is asking them about it. The plan was discussion/speculation like what you're talking about, then at some point during the summer they'd say
"look at the titles".
Somebody figuring that out early fukked everything up though. So after the anagram, who left the note is pretty obvious. They should've known better because this fan base is nuts when it comes to details. People actually contacted Rich Eisen because they heard his voice in the intro to the first episode this season, and were trying to figure out what podcast the janitor was listening to, to nail down how long it is after Walt dies. It's like a month and a half after the finale of "Breaking Bad".
You can't surprise people like that very easily.
Fred.