Him coming in light doesn't mean he'll be trying to out box Usyk. Might just mean he has recognised his stamina issues in the past and also he needs more speed to deal without someone who moves as well as Usyk. I also doubt Usyk will just be running the whole fight, he's the smaller man and with Joshua now more consistent jab he'll be looking to cut the distance and unload at times, especially later in the fight and Joshua will need to be fleet of foot as well to keep Usyk on the end of his jab so coming in light will benefit Joshua.
Don't take much notice, he says this sort of thing because he thinks its funny not because he believes it.
Coming in lighter could affect his chin, less weight means less absorption of punches. Though for this fight it may not matter.
Doesn't matter what he does Usyk is the superior man, better fighter in almost every department. True winner. There's only one winner.
And here is the one I was looking for. Do you want to apologize yet for questioning the character of the greatest fighter of this generation? It would be the classy thing to do.