Brock Lesnar’s contract expires at WrestleMania, though his non-compete clause extends until August and he might be required to make promotional appearances of some sort from April to August. There has been nothing clear on whether or not he will re-sign with WWE. Last time Brock had contract negotiations it came down to the very last day and involved Brock walking out of a RAW at one point, which lead the show to being re-written around his absence. If Brock re-signs it is believed he will work a program with Bobby Lashley sometime following WrestleMania 34.
Cena vs. Undertaker has been rumored and if WWE goes that route, it will be after Elimination Chamber, since Cena will be involved in the Elimination Chamber match. The Rock was being discussed as teaming up with Ronda Rousey to face Stephanie McMahon and Triple H, but it will depend on his movie schedule and if he will be barred from wrestling due to insurance reasons.
On Ronda Rousey, Dave Meltzer reports — and the internet will love this — the key reason that Ronda has been brought to WWE is to help elevate Stephanie McMahon to being a mainstream name the way Vince McMahon is. The PR, ratings and subscriptions were secondary, Meltzer was told. Vince isn’t getting any younger and just like his feud with Steve Austin brought Vince’s name to the minds of the general public in the late 90s, the goal is for Ronda to feud with Stephanie, a la Vince vs. Stone Cold, to help make Stephanie McMahon more mainstream. Meltzer notes Ronda was the most searched female athlete of 2017 on the internet.
A rumored Seth Rollins vs. Jason Jordan match at WrestleMania may or may not happen depending on Jordan’s injury status. Finn Balor/Seth Rollins are being discussed as a possible tag team to feud with The Bar, and they have wrestled recent house shows together.
Asuka still might end up facing Charlotte, despite WWE saying on RAW she would face Alexa Bliss, as WWE has gone back and forth on Alexa vs. Nia, Charlotte vs. Ronda, Charlotte vs. Asuka and even Ronda vs. Asuka for WrestleMania at this point.
Source: Wrestling Observer Newsletter