The World Government’s realization
Back to the World Government’s large Strawhat, the middle finger in disguise they took off of the Leader of the Ancient Kingdom. For over 800 years, they believed that they’d possessed Uranus. They had no idea how to operate it and spent centuries trying to decipher it. They had it frozen and kept in a well guarded place for that reason.
Then a boy shows up wearing a small Straw Hat. He stirs up some trouble in Alabasta and a few other islands, but he’s nothing dangerous. He enters the New World a couple of years later, goes down to Fishman Island and takes out Doflamingo, but again, he’s merely one of many troublemakers, and people like Kidd and Blackbeard are far more dangerous because of what they’ve done in regards to murdering people. Then he builds himself an entire fleet in a couple of days, infiltrates an Emperor’s territory, allies himself with the Germa kingdom and Bege’s crew, takes said emperor’s crew member (Jinbe), defeats her first commander, trashes her main island and runs away nearly unscathed. After this the World Government has taken notice and tripled his bounty to 1.5 Billion, something that was believed to be almost impossible after a certain threshold.
And that’s not all. He is leading the Supernovas and Wano Country in the battle that will lead to the fall of the Emperors Kaido and Big Mom.
Now the similarity between the 2 Straw Hats starts to take shape. Before all of that, they were 2 separate and unrelated entities, but it’s different now. Seeing this all take shape, a mysterious and important figure from Mary Geoise takes Luffy’s bounty and I’m guessing Roger’s as well, goes down to the vault that holds Uranus, compares the bounties to the large Straw Hat, and it clicks.
“The hat is useless, we’ve been fed lies through generations. The real threat is the kid with the small Straw Hat”.
*Theory by Steins-Fate