Why no confrontation?

According to the Wrestling Observer, Vince McMahon believes John Cena and The Undertaker didn’t need to make a confrontation with Undertaker at WrestleMania 34 “official” because it’s not selling any additional tickets or WWE Network subscriptions at this point, and that people who are already going to watch WrestleMania are invested enough they’re interested in even the chance Undertaker shows up.