At the time? Not really. The Soviets disavowed responsibility and, despite international observers who supported the German contentions, claimed that the Germans had committed the massacre and were trying to frame the USSR for the atrocity. The Western Allies were maybe skeptical in private, but weren't going to press the issue despite pressure from the Polish Government-in-Exile based in London. When the war ended, the Soviets included charges for the massacre in the war crimes that ended up being prosecuted. The USSR would continue to deny involvement through almost its whole existence, and it wasn't until the late '80s that any movement toward admitting what happened, and only in the 1990s did real reevaluation of the whole matter begin (in a sad coda to the matter the plane crash that killed Polish President Lech Kaczyński in 2010 was taking him to the 70th Anniversary memorial of the massacre being held in Russia.). Once the Cold War started up of course, playing nice with the USSR was no longer an issue, so responsibility was debated in the west, and there was more willingness to acknowledge Soviet culpability.

However, in regards to what the massacre says about the Soviets in hindsight, well, it fits very nicely into the larger picture of Soviet-Polish relations during the Stalinist era, part of a concerted campaign to weaken and control the region. This is something I've written a good deal on in the past, so I'll direct you to this post, but I'm happy to expand on it if I can!