Two Top WWE WrestleMania 34 Matches Scheduled?

As reported by Dave Meltzer the two top matches for WWE WrestleMania 34 are currently being scheduled.
According to Meltzer, Brock Lesnar vs Roman Reigns and John Cena vs The Undertaker are expected to be the main event matches for the event taking place in New Orleans in April.
Lesnar vs Reigns is a match that has been rumored for some time now, and would likely be for the WWE Universal Championship match.
Whilst The Undertaker has not competed in a match since his defeat to Reigns at WWE Wrest