In Reply To #17
To be fair about Tales of Monkey Island... Besides the one designer stating that Tales was set after a "fictional" Monkey Island 5, said before the game was released and was still being finished (concept information is not too reliable).
The game actually doesn't talk about any fictional monkey island 5. It pretty much starts out as previous Monkey Island games for example such as the sequence between Monkey Island 2 and Monkey Island 3, in which we are only given hints about his adventure and escape from the Carnival of the Damned.
Also of note the game is a joint operation by Taletale and Lucasarts which specifically noted in the introduction video, and much of the staff are the staff behind the previous games. Sure Ron Gilbert isn't part of the staff, but he hasn't made the games since the second one.
For all intents and purposes Tales of Monkey Island is Monkey Island. I bet that any called "Monkey Island 6" (noting that hte series hasn't actually held any numbers other than the second game), will likely take place after Tales of Monkey Island.
As for knowing the Secret, well its been stated by Gilbert that is a runnin gag. Even if he had been continuing to make the game he probably wouldn't have explained the Secret.
As a related note an early gag in Tales from Monkey Island explains that Guybrush still doesn't know what the Secret is. So any finding Secrets has to take place after the game (I'm pretty sure the Secret isn't going to be in Tales).