As excited as I was about this when I got into the travel-awards game 6 years ago, I never ended up making much use of it. We were able to go to Vegas once and get some benefits with the status match . The second trip was in March 2020 and the MGM hotel cancelled our stay the day we were supposed to check in (thanks Hyatt Place - Silverton for taking us in that night, and numerous other Hyatts that week for not abruptly shutting down and kicking customers to the curb last minute).
And, I never saw any advantage to booking through Hyatt.com over directly with MGM.