Hyatt and MGM have a partnership that dates back to 2013. They each offer members in the other program status matches – not one time matches, but rather status in one program ‘equals’ status in the other.
And the status year in each program ends at a different time. This creates an opportunity to still have status with one program, after your status has ended in the other, and to use that to ‘match back’ to regain status – in perpetuity, or as long as this tactic has continued to last (and it’s lasted for years).