Some time ago Hyatt started a partnership with MGM’s MLife scheme which matched Diamond members to MLife Platinum status. Not the most useful match unless you happen to be at one of the MGM properties where you do get some benefits, and as a Hyatt Diamond member you match to MLife’s Platinum status.
You do get Priority Check-in, are supposed to get room upgrades, as well as priority valet and taxi service. Better than nothing.
There were wrinkles when Hyatt and MGM first joined up, but these settled down and I had a stay at an MGM property which I credited to my Gold Passport account and obtained the benefits given.
Roll forward 2 years and despite continuing to be Diamond Gold Passport, MGM dropped the status match and I am now their most basic of members.
The matching scheme is still going on but has to be done on the phone. I called a week ago and am still waiting. I have about three weeks until I get to Vegas (baby), and hope it will be fixed by then.
However if, you like me, did the match before – check you may have to do it again. This was the original information about the matching: