#3 & 2 To establish Brock Lesnar as the biggest heel in WWE and let him pass some torch to a Superstar at WrestleMania 36
Brock Lesnar is already receiving a ton of hate from the fans. First, he enraged us by winning the Universal Championship and now, Vince McMahon had handed him the Money in the Bank briefcase. If he successfully cashes-in his briefcase against Seth Rollins, then it would ensure that Lesnar receives a crazy amount of heat from the WWE Universe.
If Lesnar waits for some more months before cashing-in, then the fans may not hate him as much as they would do if he wins the title today. Rollins is enjoying his first-ever Universal Championship reign and if it comes to an end because of The Beast, then it would only anger a ton of fans. If Lesnar is going to retire next year, then this move could do wonders for a Superstar who would beat him for the title at WrestleMania 36 and assure he is retired.