They shouldn't censor it. It just shows massive double standards, given what is and isn't censored.
Also, to those of you arguing "But hitler was the worst guy ever thus..." unless you really know the facts(i.e, are qualified enough to show that your opinion is informed) then this is just foolish. Yes, he was a terrible person. However, he is not unique in this, and I have seen it argued that other people(usually stalin) were just as bad, and as I recall they weren't weak arguments. I am not claiming to know all the facts, which is why I am not arguing one way or the other.
However, that is all completely irrelevant. Even if Hitler was "worse" than Stalin, where is the line. Are you saying that Stalins attrocties were not bad enough to warrant censorship while Hitlers were? How many millions must someone kill before they deserve censorship?
The argument that the symbol only represents the nazis is similarly flawed. At what stage is a synbol more associated with one thing than any other? This will also vary widely.
At the end of the day, any such decision over what is censored is very arbitrary. There are a huge number of groups in history who have done terrible things, and an equally huge number of symbols associated with them. Should the British flag be banned as a result of colonialism?
They let you have a gun as a symbol. This is something designed purely for one intention: to kill people, and has undoubtedly killed more people than any single regime. And yet, the game is about guns. You carry a gun for the overwhelming majority of the game. Banning it would be idiotic.
Any censorship is essentially arbitrary and pointless. They should either allow no emblems(a limited choice is essentially pre-emptive censorship, so unless they remove anything remotely offensive, it's a bit silly), or complete customisation.