Don't table tennis players learn to predict how the ball will act based on their opponents movements? Seems like if they aren't able to do that with a robot opponent (who doesn't look or behave like a human) then they wouldn't be able to play at their best.
You can predict the movement of the ball (speed, direction, spin) based on the movement of the bat relative to the ball. What the rest of the player's body is doing is irrelevant to predicting what the ball will do - but relevant to predicting where they will be when you make the return shot.
Humans use every clue they can get to predict the trajectory as early as possible. For example most players use a roughly similar technique for a certain stroke, e.g. the forehand topspin. They also tend to have a pretty narrow angle that they usually play it, relative to their body and their movement. Players use that predict where the ball will move, and position themselves accordingly. And they start that movement before their opponent has touched the ball.
Some players can deceive others by bending their wrist right before ball contact, which sends the ball in an unexpected direction (but that usually comes at the cost of an increased risk of missing the shot).
Similarly, the size of the stroke limits the pace (and spin) you can apply to the ball; when the opponent starts a short stroke, you can be sure the shot won't be fastest, and move closer to the table.