Agreed he hasn't lost yet so why mess with his style at this point.
Well, changing styles is not appropriate to do now. There's no need for it and not even a necessary thing to do just to have an advantage. Both boxers reached their respective status because of their usual styles. What they do is enhance and improve it.
In any strategy, the right timing plays a key role. That's what both will try to avoid.
If at some point they found the hole on defense, that might be the
"turning point".
A single mistake that will give an opening from either fighter will not be wasted for sure, its an opportunity to make the opening
and try to put down their opponent. I'm sure there are improvements and adjustment but in terms of changing styles that might be
a risk. Like what you said, timing is very important and since both fighters already achieved, the top, both are more focus on how
they can see the best one to bring their solid attacks to win the fight.