So the Undertaker apparently left it all in the ring last night ... literally.
When the match was over, after Taker was defeated for the final time, he stood in the ring and removed his gloves, his hat and his coat and left them there in the center of the ring.
And long after the Main Event had finished and the last of the fans had filed out the doors of the stadium, as the crew was dismantling the ring and the rest of the WrestleMania set, the Undertaker's Hat, Coat and Gloves remained in the center of the ring where he had left them.
It certainly seems like the kind of thing a company would do as a ritual to signify that a beloved venerable performer was hanging it up and retiring.
There's been no confirmation at this point, but all signs point to this being The Undertaker's last WrestleMania, if not his last match.