Bearing in mind I have no legal background, this is just my understanding.
The motion TMZ have brought is to stop the ex-reporter from testifying at all.
They are all speculating on what he will say, for example, who leaked the video and divorce to TMZ. But no-one knows if that is what he will say.
The judge ruled she would not the ex-reporter from testifying.
However, she made it clear that if he starts to testify about leaks, then she will deal with any objections when it happens.
So, the ex-reporter can testify (but still not sure if JD will call him)
But, we do not know what he will say. He very well may not say who leaked stuff to TMZ, so don't get too excited 😁
Long and short though is TMZ and AH team are pissed off.