The live audience being able to see fighters’ heart rate monitoring in real time would be incredibly interesting but at the same time I could see why athletes might prefer to keep this data close to the chest (no pun intended). From a legal privacy stand point, it still constitutes personal health information.
As far as strategy goes, it also gives away part of a fighter’s game. “Poker face” is a critical part or the arsenal, Hiding or playing off how hurt, tired or scared you are. knowing before the first round, who is freaked out and who’s cool as a cumber. Having a little cardio counter beside each name on the screen would be very cool, but I don’t see this going further than a fighter’s medical file unless consent is given to share it.