When Roman Reigns eliminated The Undertaker at the Royal Rumble, we got the start of the setup to the planned Roman Reigns vs. The Undertaker match at WrestleMania 33.
Yes, Vince McMahon hears all the boos that Reigns gets whenever his music plays and he walks out, but Roman vs. Undertaker is a match he has reportedly wanted for a long time and given The Deadman's health, this could be the last chance to make the match a reality.
On another interesting note: The Wrestling Observer Newsletter is noting that there are discussions for this to be a generational passing of the torch which, given how the WWE Universe generally feels about Reigns, seems like a pretty difficult thing to pull off.
So, this could mean an official heel turn for Reigns, but The Wrestling Observer is also saying that the long-term goal for the WWE is still, if you can believe it, for Reigns to be the face of the company.