WWE has pointed out that only four men have been the lead commentator at WrestleMania: Vince McMahon, Gorilla Monsoon, Jim Ross and Michael Cole. Tonight, Tom Phillips will be #5.
Only 4 men have called Lead at #WrestleMania: Vince, Gorilla, JR & Cole. Tonight a 5th joins…congrats @TomPhillipsWWE! pic.twitter.com/57aqwsdX2v
— WWE (@WWE) April 2, 2017
Joey Styles actually called ECW matches at WrestleMania in 2007 and 2008, however.
Here is a chart via Wikipedia (click the image to see a larger version):