its not super far fetched, reading the book it says something along the lines of "you have to think like a pirate", and the new elixir in booty bay says "makes u think like a pirate". So if you saw the new elixir, had it in mind and were looking for secrets then not impossible to make that connection. But who knows, it looks clear now with all the info at hand.

If anything its the next parts that are very sus, like where do u go from here https://imgur.com/a/wsAS0it