According to the Dave Meltzer of the Wrestling Observer Newsletter, the two top matches for WrestleMania 34 are scheduled as Brock Lesnar vs. Roman Reigns for the Universal Title and John Cena vs. the Undertaker in a single match.
The feeling for some time has been that the angle for Cena vs. Undertaker will be shot in two weeks at Raw 25.
WrestleMania 34 is set to be held on April 8, 2018, at the Mercedes-Benz Superdome in New Orleans, Louisiana.