"We didn’t hear the whole story during the Holocaust." (emphasis mine).

It seems meant in the sense of back then people weren't hearing about what was going on in near real time, and only afterwards was the full dimensions of the horror discovered.

Mind you, I don't think we are hearing the whole story of this Holocaust in near real time either: it's not for nothing that Israel has blown up the Hospitals (were the dead were counted), has murdered over 1000 journalists and is blocking them and aid organisations from entering Gaza - all of which stops people outside from discovering the full scope of what the Israelis are doing in Gaza.

We are hearing enough to know its a Genocide, but the full dimension of the thing (possibly with it, in scope and in methods used, already being or well on its way to be a new Holocaust - I mean, just look at how this piece from CNN unwittingly reveals how they're sistematically using buldozers to turn the appartment buildings they blew up into in situ mass graves for the victims, dead or even still alive) will only be discovered later if at all.

Just a bit of history, in WWII the Allies didn't know for certain that the Holocaust had occurred. Remember that it was the 1940s, information could travel quickly but only so much. It wasn't as easy for them back then to pickup the metaphorical 'signal' of the Holocaust happening to the 'noise' the rest of the war was making. So while there were rumors of mass executions of Jewish people as early as the summer of 1941, it's often said that the Allies didn't know about the Holocaust until winter 1945. Now when the Allies went from ignorant, to suspicious, to all but certain but with doubts and finally to certain without a doubt has been debated for decades and will probably be debated until the sun expands and swallows the earth whole. There was definitely a lot of hateful rhetoric being spouted about Jewish people in the 1930s that maybe should have been stopped before it nearly took over Europe, but looking back at history we have the advantage of hindsight.

I'm hoping they mean that we were using slower forms of communication without immediate evidence and we still stepped in to help...

But I'd rather them say that.

Nobody of the normal populace knew. Do you really think the jews would get on those trains without putting up a real fight? Bringing their belongings, jewellery in suitcases to Dachau, Auschwitz?

Does that sound like actions of someone who knew what was going to happen?

Yes, a lot of people knew what was going on. A lot of people, more people, didn't know shit. The problem was not that. The problem was that they didn't care.