I think it's this one [1] and this is the text from it without WSJ paywall [2], but the main issue was with the video included in WSJ not in the article text itself. If I remember it correctly it is few clips from Pewdiepie's videos stitched together out of context to make him look bad. Note that I am not saying that he did not push his jokes too far but still a "serious newspaper" should not take short clips out of context, like if you took any 10 seconds from Dave Chappelle last special that would make him seem like a horrible person.
Sorta off topic but I read a “not that we’ll know old novel” recently and was surprised to find out that PDP read it as party of his book club (which I didn’t know existed). It changed my view of him a bit that he reads serious books and talks about them, whereas I thought he only fucked around to entertain children.
Yeah, there certainly is a ton of videos where he just "fucked around to entertain children" but he said it himself that he could just keep doing it forever. There was more serious side to him, like the book club, but I have no idea what he does now.