As noted, Brock Lesnar made a surprise return at the WWE Money In the Bank pay-per-view and won the men's Money In the Bank Ladder match main event. WWE did an angle earlier in the night where Braun Strowman took out Sami Zayn, leaving spot open for Lesnar to return.
Lesnar was hidden away from most everyone else in the backstage area, according to PWInsider. There had been some rumors earlier in the day of Lesnar appearing, but no one could confirm he was there. Only a small group of people were aware of Lesnar's return before he appeared backstage in the Gorilla position with WWE officials.
As we've noted, Lesnar vs. WWE Universal Champion Seth Rollins has been rumored for WWE's Super ShowDown event from Saudi Arabia on June 7, but there's no word yet on if this will be his MITB cash-in or just his WrestleMania 35 rematch. WWE will be announcing more Super ShowDown matches on RAW.