The WSJ? What are you talking about? It's opinion pages are famously conservative.
Some proportionality would be good. “Extreme” when used in the context of political ideology implies some form of totalitarianism; i.e., Nazism, Fascism (extreme right), Stalinism, Maoism (extreme left).
The WSJ, from the little of it I read, tends to adopt generally classical liberal or libertarian positions; i.e, moderately right-leaning economically, moderately liberal on social issues, generally in favour of more liberty across the board, and thus opposed to authoritarianism.
There's a valid debate to be had about the merits of these positions, but to describe the WSJ as “extreme right” does an injustice to the many who've suffered and died – and who continue to do so to this day – due to genuinely extreme political ideologies.
However I have seen another bit of your logic elsewhere and strongly disagree with it: the idea that mislabelling (or even correctly labelling) something "does an injustice" or "is a disservice" or "would be offensive to" people who died in the past at the hands of someone/something. We only have an obligation to make the lives of current and future people better: people who have died because of hatred would surely appreciate us doing our best to combat hatred in the modern world.
I agree that making life better for people today and in the future is what matters most. And I think an important step in doing that is to heed the lessons of history, which includes having sympathy for the suffering of those who've gone before.