If you don't care about evidence then this rule is therefore more about the optics - just the appearance of doing something. And because you don't care about evidence you can't then make claims about "making sure" because then you stray into the land of probabilities and possible guarantees. Which you can't do because that requires evidence to be even remotely useful.

If the rule has any validity then you ALSO can't tolerate people talking before the ride. Can't stop one activity and allow the other. Talking is a known infection vector since it can easily fill a space like a room with a significant viral load. This is how people get infected simply by entering a room full of infected air that has suspended viral particles in it.

But can you fill an area with a significant viral load when that area happens to be an open-air roller-coaster moving at high speed?

So evidence does matter. Either way.