So if Michaels hadn't relapsed and fallen into a Doink-confusing stupor, he would've faced HHH at Wrestlemania 17. What does Undertaker then end up doing on the show? It couldn't have been Taker/Kane against Haku and Rikishi since Rikishi was already hurt. The Brothers Of Destruction teaming up in some kind of hardcore tag match against Big Show and Raven seems like kind of small potatoes for Undertaker at Mania in his home state.
Shawn wasn't facing Hunter, he was scheduled to interfere in the match and set up a later feud. It was always HHH v Undertaker.