According to Cagesideseats, the current expectations are for The Miz to regain his coveted Intercontinental Championship from Roman Reigns at RAW's 25th Anniversary show. While this should be considered speculative, this is a trigger WWE will have to pull sometime before WrestleMania.
However, with so much time between now and the April mega show, WWE may choose to have Miz and Reigns enter a multi-chaptered feud over the prestigious title. Seeing that Miz and Roman are some of RAW's most established names, they could use one another to heat up for 'Mania.
Then again, they could part ways after a Miz win at RAW 25.
The Miz has monopolized the Intercontinental Championship since the 2015 brand split, and when he possesses it, WWE is a healthier ecosystem. So while Reigns fan would hate to see him suffer such a high profile loss; it would be for the best. Besides, ever since WrestleMania 33 shut off its cameras, WWE has been angling for Brock Lesnar and Roman Reigns to headline WrestleMania 34.
However, if the Miz does indeed yank the IC belt from Reigns next Monday, that may free up Roman to win the Royal Rumble 6 days later. At this moment, the only person with better mathematical odds than Reigns outlast the Rumble is the frontrunner, Shinsuke Nakamura.
Regardless of what transpires in the next week, we can say with confidence that Roman Reigns is not winning the Royal Rumble. Other than retiring* the Undertaker, WWE did their best to slow play The Big Dog in 2017. He endured a pay-per-view losing streak while hardly sniffing any title picture then shared his spotlight with the Shield to close the year. But now, Reigns is ready to launch, but WWE is all too aware that a Rumble win would be a bit heavy-handed. Especially since it's in Philadelphia, a city that vomited on Reigns' 2015 Rumble victory.
So for now, consider Miz a slight favorite at RAW 25, but in this era of WWE, it's never a bad idea to bet against Roman Reigns.