Marriott Rewards and SPG programs are merging on Saturday next week (August 18, 2018) while still keeping their old names (for now). The new combined name for these programs is announced in early 2019.
Last year, I reached lifetime Platinum status with SPG that was minimum 500 nights and 10 years as Platinum members (although everyone knew that the program was going away). The new combined program will have Platinum Premier status too and only those that qualify for the lifetime status this year can get it.
You can access Marriott’s page for the combined program here.
I just passed the 750 nights mark last week that is the minimum for Lifetime Platinum Premier status combined with 11 years of Platinum status with SPG (10 years is the requirement).
Here are the lifetime status levels in the new program (Premier is one time only):
The main benefits of the Platinum Premier status over Platinum are the higher bonus 75% compared to 50% and higher upgrade priority.
Considering that the Ambassador status i(underwhelming) n the new program comes with $20K price tag, I cannot see any reason to be part of the program beyond 2020.