alt Hacker NewsThe press release following the bombing of Hiroshima specifically stated which method of refining Uranium was used. The U.S. spent a great deal of time, effort, and money on researching and testing four different enrichment systems. Just that one detail saved the Soviets 3/4s of a sizeable chunk of the A-bomb effort. Sometimes you don't need to leak much detail to give away a great deal.
Do you have the press release in question? I'd be very curious to see it. All I found at a glance was Truman's well-known one (https://www.atomicarchive.com/resources/documents/hiroshima-...) which was followed by the Secretary of War's (https://www.ibiblio.org/pha/policy/1945/450806b.html) and neither seem to mention anything about enrichment methods or even the concept of isotope separation.