Then probably he heard about the rumor beforehand, and posted the article to disprove it himself. Hence why in the comments he incited people to read the article instead of just reading the headline, as people were taking it as confirmation instead of a debunk.
So if it was to disprove the rumor, why did his tweet say "E3 2016: Devil May Cry 5 Is Happening", instead of, you know, "not"? It's obvious misleading that gives him cover to say that.
Moreover, his reasoning makes no sense. He said it was to get people riled up so they would go at Capcom to ask for the game - However, back when that original mocap pic was posted months ago, they actually got in a bit of trouble for it with Capcom, who asked them to take it down because people were really incensed about wanting a new game and bothering them about it.
So basically, with this Reuben would have done exactly what he was explicitly told not to do.
Unless it's real. In which case he has an out with a solid excuse for having teased people so hard, and Capcom doesn't need to put up with fan demands too much because the reveal is literally two or three days away.