Kurt Angle announced last night that this triple threat match for the Intercontinental Championship is officially on.
If given time, it's a match that can potentially steal the show. These three had a fantastic three way IC title #1 contenders match on Raw last May, which WWE.com listed as WWE's 10th best match of 2017, so there's all sorts of potential for greatness here.
I don't see Miz retaining the title, I have a feeling every title on the main roster will change hands at WrestleMania, though it's a complete toss up as to whether it's Balor or Rollins who wins. Regardless, this will not be the last of Miz in the IC title picture or the last time we see him as champion. Miz will tie and, at some point exceed, Chris Jericho's record of winning the title 9 times and he'll eventually have the most cumulative days as champion.