I can pass along that there’s another angle to the grunts (having played a lot of tennis). The sound of the ball hitting the racket provides useful information, particularly for a mishit or a powerful shot — because you have to move up or back quickly to cope. For years, top tennis players have used grunts and shrieks to conceal this sound from their opponents (e.g. I always thought Sharapova, and Seles years ago, were prime offenders). There’s no need for such noises as a function of effort, or events like NBA games would sound much different. But the tennis authorities haven’t done anything about it.
In table tennis, where I have a very long involvement, the spin on the ball is tremendous in high-level play — so much so that a concealed dead ball (with no spin) is a very effective tactic because the opponent will err by responding to the spin that isn’t there. Years back, a totally dead racket covering was developed for this purpose; even worse, it tends to continue the spin so that the originator effectively gets the reverse back of what he put on the ball. A top US player with whom I grew up developed a style where he used only one side of the racket for both forehand and backhand, while frequently flipping between the spinny and dead sides of his racket that were colored the same. Players could hear the difference, however, as the dead side made a little thud when struck. His innovation was to stomp his foot on the floor each time he struck the ball (going beyond the norm of the time of just stomping on the serve). A subsequent regulatory change required rackets to have one red and one black side, to facilitate keeping track of which rubber covering is being used for a given shot.