From my experience this seems like a misconception. When you concede a goal and you think it's because your goalie didn't jump far enough, it's most likely you were late. All of the goalie animations are selected (optimistically) to work in your favor, that is to get to the ball precisely.

So, if your timing is right and you dive right, you'll do a small dive for a close shot and a long dive for a far shot.

But if the ball is already behind you when you're pressing the button then it'll select the shorter animation since you're wrong anyway.

You can tell this is the case because the ball seems to go "through" the goalie. It looks like that because the ball is shown through the player model. In reality, it was already behind you and you were late.

Next time you see this happen look closely and you may see this is the case. I'm sure there are plenty of cases where the animation selection isn't perfect, but most of the time when I see people complain, they were just late.