Congress will get this information.
The courts will uphold a request that cites Impeachment. Likely after a long fight.
Don’t count on it.
The courts are not completely gullible enough to believe that reciting the word impeachment means anything goes. After the Mueller fiasco courts are likely to demand some evidence there is a real likelihood a crime was committed and they are not simply doing it to leak to the media. Since they have bragged endlessly about doing just that, I don’t see it happening- especially with Trump’s businesses.
The correct ruling would be:
Since the law that prevents Grand Jury testimony to be revealed was passed by Congress then it is up to Congress to change the law. The Court should not be involved.