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.