Nope.
Shawn Michaels will face undertaker at wrestlemania XXVI
At WrestleMania 1, The Undertaker did not wrestle anyone. The Undertaker wasn't in a WrestleMania match until WrestleMania VII (7).
No one knows that yet, but at WrestleMania 27, Triple H will face Undertaker.
Kane
Edge
The Undertaker is coming back to WrestleMania 32 to face Sting and then retire the day after WrestleMania.
Shawn Michaels
Randy Orton
john cena
Yes
Triple H
He will beat HBK at wrestlemania 26