The Holocaust played a very small role in the Allies' strategic goals. Their main priority was to end the war by defeating Hitler militarily, and forcing him to unconditionally surrender.

This meant that any negotiation was restricted and frowned upon. This even extended to the Yishuv's attempts to rescue Jews from Nazi mass murder in Hungary. When it was discovered that such negotiations were taking place, they were leaked and led to a scandal. The ones doing the Negotiation were framed as "consorting with the Enemy". Especially by the Soviets. This led to the Negotiations being shut down.

To answer your question about the Concentration camps, we have to look at it at a case by case basis. Several reports about Auschwitz were given to the Allies by both Polish resistance agent Witold Pilecki, and by escapees like Rudolf Vrba and Harald Welzer. The West simply did not take them seriously and ignored requests by the American Jewish Congress to bomb the rail lines to Auschwitz, both because they had no capability to, and were themselves very anti-Semitic and indifferent to the Jews.

The next case is the Western KLs like Buchenwald, Dachau, or Belsen. It's important to remember that the US got involved in WW2 primarily because of Japan's attack on Pearl Harbor. That was the story that the US public was interested in. Accordingly, the US spent most of its military efforts in the Pacific. 5 to 10 times more than what the US had in Europe. Most of the US news prioritized military victories in the Pacific, especially with regards to the Philippines, seen as a valuable American Ally that suffered under the Japanese. Much like in the present day, the US media at the time focused more on glorifying the US military's performance than focusing on the plight of civilians like Jews. Simply put, even though the Allied leadership knew about the Holocaust, they did not dwell about it too much and prioritized defeating Japan and Nazi Germany militarily, and accordingly the Media did not pay too much attention to it either.

The end result was that the Allied troops on the ground only had a vague idea about the Persecution of the Jews and the conditions in the KL. They were in the dark, which is why a lot of attention was given to Dachau, Buchenwald or Belsen after liberation. They honestly did not know what was going on, and were genuinely shocked by what they found when they freed the Camps. Hence, memorial efforts and the immediate revulsion, which resulted in Allied troops often taking impulsive revenge on any SS troops they found.