WWE’s schedule remains packed, most of the time, no matter what. Even the ongoing pandemic didn’t stop them from hosting WrestleMania and SummerSlam in style. In general, these are such of the shows where at least a couple of marquee matches remains determined from the get-go.
Things are pretty different though, this time around as they have to figure out different issues before rolling WrestleMania, again. The venue could be a huge matter of discussion as WWE may have to relocate for the second year in a row. The overall change could also affect their creative plan aka the main-event planning for the evening.
Wrestlemania 37: WWE No More Considering Original Main-Event Match

As per the recent reports, the main event match at WrestleMania 37 was supposed to be Edge vs Randy Orton in an I Quit match. Vince McMahon booked this match as soon as Edge was injured at Backlash 2020. His return could’ve easily set this match up and thus cause a similar bout at the grandest stage, for the second consecutive year. But now, it could be up in the air.
Edge Reveals When He Wishes To Take Retirement From WWE
It was noted in the Wrestling Observer Newsletter that Edge vs Randy Orton at WrestleMania 37 does no longer have a clear direction. As of now, a few things are being considered from the roster perspective before sorting out the plans for the ‘show of shows’ that was apparently going Hollywood, next year. Here’s more from the source,
“At one point WrestleMania was to be headlined by Orton vs. Edge in an I Quit match. It was not a lock that Orton would be champion, but it was something under discussion. At last word there was no longer a 100 percent clear main event direction for the show. If Orton is going to win the title, then Lee should beat him here to set up Orton vs. Lee title matches, since they have no other babyfaces ready for Orton with the way they’ve booked Mysterio and Owens (who Orton beat on TV) and with Black turning.”

Since WrestleMania location was set from Hollywood, it was heavily rumored that WWE could also heavily try to rope in The Rock for one final match, perhaps against his cousin Roman Reigns. If the venue gets changed then that option may not be considered, anymore.
It should also be noted that Drew McIntyre has done a tremendous job while being the WWE Champion starting from last year’s WrestleMania. He’s the main babyface star of Monday Night RAW who is carrying the load. So you never know whether WWE chooses to book him in another marquee match for the second year, based on long-term booking plans.