I was wondering if a rematch took place at 154lbs would there be any kind of extra drug testing. Or is that a point of view only shared by the Mayweathers?

I believe its the only point of view from the Mayweathers. Especially Floyd Sr. He was embarrass after the Hatton fight on how easily Pacquiao dismantled him Floyd Sr. talked so much junk before the fight and during training camp that he didn't even take Pacman seriously. How many times during HBO 24/7 did Floyd Sr. arrived late for training camp. Even on the night of the fight he showed up 30 minutes before curtain time. Whats even worse after Hatton was knocked out where was Floyd Sr? He puts himself so high on that he is the greatest trainer ever he had to save face. So what he does he starts to spread lies and speculations. Now I'm not denying that he is not a good trainer but let your work speak for itself. You don't hear the Manny Stewards, the Dundees, the Cus Damatos, or the Eddie Futch's screaming nonsense rhetoric about being the greatest trainer ever. What i don't understand on why Floyd Sr would say that there is nobody in history that small that has beaten the bigger guys like Pacquiao is doing. Which is not true. If he really knew boxing the name Sam Langford should ring a bell. He was 5'6" 1/2 and fought from lightweight to heavyweight. He had great power in both hands, speed, and great countering skills. In my opinion he was probably in the top 5 p4p fighter of all time. And due to the racism of the past he didn't get a shot at the heavyweight title. Jack Dempsey didn't want to fight him. He claims he already knew the outcome of the fight. Even when Langford loss a close unanimous decision with before champion Jack Johnson. After Johnson won the world title Johnson refused to fight Langford due to " Langford could not afford his appearance fee."
What about Henry Armstrong. Back in the day there was only 7 weight classes. Henry won and held at the same time the Flyweight, lightweight, and welterweight title. went up to middleweight and got screwed out of the middleweight title. He would of have own more than half of the boxing titles. He is the reason today sanctioning bodies frowns upon and discourage a fighter to hold belts in multiple weight class.
What about Floyd Jr? He claims that he started boxing at 106lbs(amateur) Just like Pacman. Floyd won titles in 5 weight classes and beat bigger men and nobody has accused him why? And he is still undefeated. That's why i don't give Manny such a hard time. Most fighters who is from third world countries they don't have an extensive amateur career and their training is basically is on the job training. You had 16 year old teenagers fighting 25-30 year old grown men. Look at the careers of men like Julio Caesar Chavez, Winfred Benitez, Salvador Sanchez, and Antonio Margarito. Even Manny started his professional career when he was 16 and his two KO losses came before he was 21. So he was in the process of learning and maturing. Plus in most people your body doesn't fully mature until the age 25.
I do believe boxing should be regulated by one governing body so the bests fighters fight the the bests. All related drug testing should come from the commission not one fighter who thinks he is bigger than the sport that made him. I think if Cotto does fight Manny again I think this fight will be intriguing because of Cotto's new trainer will be an "X" factor. Steward saw Cotto's mistake in that fight so he will correct it. But like many others I want to see Manny take on Marquez so he can try shut him up for good.