Yah
It’s a fan theory. I think Gideon Cahill and Li’l Gideon are the same only because of name. If this was a true canon fact, than that would mean the 39 clues would take place after wierdmaggedon
Gravity Falls x The 39 Clues theory: Gideon’s full name is “Li’l” Gideon “Gleeful” CAHILL
I mean maze of bones
Look at the last part inside the book