I still think there's scope for Reigns to have a heel run, even if he's set to be the company's super face going forward. But I don't think this years Wrestlemania is the place to do it by having hi face Taker.
I think we will have an Undertaker match, but against who? It's up in the air for now. But it's that a good thing? In past years we've grown used to knowing who gets to face Taker at Mania, isn't it exciting not knowing who he's going to face for once? Just because we don't know who it's going to be or there isn't an obvious candidate jumping out doesn't mean it won't happen. WWE are aiming for a record attendance at the stadium so I think given the injuries they have, they NEED to have Taker on the card to make that happen.