Probably not the best idea(or match) but I think it wouldn't be too bad. When has the Undertaker defended his undefeated streak in a 3-1 handicap match? I feel they could make a decent story that could make you think the streak might be over. It would give the Wyatts a good rub by nearly ending the streak. Make the Undertaker's streak 22-0 and could possibly turn Kane face and help Taker keep the streak alive. I honestly doubt we'll see Cena vs Taker, The Shield will more than likely be broke up by then. We've also already seen Brock vs Taker too.
WM30 Match card(in no order):
Cena vs Orton- WWE title and WHC championship match.
Daniel Bryan vs CM Punk
Ryback vs Brock Lesnar
Goldust vs Cody Rhodes
Wyatt Family vs The Undertaker
AJ Lee vs Paige- Divas championship match