This leak is not helping Russia and harming Ukraine. In fact, it is confirming that Russian losses are high both in absolute terms and relative to Ukrainian ones, that the Russian offensive is going nowhere, and that the Russian security apparatus is thoroughly penetrated by American hackers or moles.
The (originally leaked) casualty figures were modified to say the opposite, actually. From the article: “Military analysts say they believe the original versions of the documents were slightly altered in some instances.
“For example, one chart puts the Ukrainian death toll at around 71,000, a figure considered plausible. However, the chart also lists the Russian fatalities at 16,000 to 17,500.”
(There was a subsequent counter-‘leak’ version that had specific different casualty figures that had higher Russian casualties and claimed to be the original figures, but who knows whether that was what it claimed or just another opposed propaganda op.)