#3. Kevin Owens doesn't get pinned at Day 1
Dave Meltzer reported on Wrestling Observer Radio that teason why Kevin Owens was added to the Day 1 WWE title match was to take the pin. According to Meltzer, this would help extend the original feud between Big E and Seth Rollins, presumably until the 2022 Royal Rumble.
However, two major things have changed since that report. First, Bobby Lashley was also added to the match, making it a Fatal-4-Way, and secondly, Kevin Owens has re-signed with WWE.
While Kevin Owens was expected to leave WWE until a few days ago, the decision to have him take the fall may have changed. If it was only a triple threat match, then it would be obvious that Kevin Owens would take the fall.
Since it's unlikely that he will become WWE Champion at Day 1, he might simply not take the pinfall and stay involved in the title picture until the Royal Rumble. Assuming that Big E retains the title, it leaves either Bobby Lashley or Seth Rollins. Big E has pinned Lashley before, and doing so to Rollins could end the chance to extend their feud. Only time will tell how it will play out.