That's a misrepresentation of what he said. From this article:

"Perhaps I got tangled in semantic weeds in my comments, particularly in view of the Conservatives' cynicism on these issues," Trudeau said in a statement. "I want to make it clear that I think the acts described are heinous, barbaric acts that are totally unacceptable in our society."

"Trudeau took the government to task, however, for using the term "barbaric" and said an official government publication should make an "attempt at responsible neutrality." He said the acts are "absolutely unacceptable" and that's not a matter of debate, but the language chosen by the government to describe them is objectionable, the MP said."

"Trudeau began posting messages around 7:45 a.m. ET, setting off a chain of back-and-forth posts with his followers: "My problem with the use of the word barbaric is that it was chosen to reassure Canadians rather than actually change unacceptable behaviours," Trudeau wrote."