Well its not the first time i ear this, once was during the Baroni vs Riggs fight,commentator was Frank Shamrock: where Baroni was ripped but out of gas and once from Joe Rogan, not sure what the fight was.
They both said that there is a really rip look but that really doesn't do any good to the fighter, doesnt mean he is in fighting shape.
Most MMA trainer that i have spoken with told me that the more muscles you have to quicker you will fatigue during a fight.
Not sure if theses statements are real or not, still look at Fedor who has a good bf% and how amazing he is.