Originally Posted by DELee

During the merge of Marriott Rewards (MR) with SPG, on April 16, 2018, Marriott updated the criteria for Lifetime elites to include what was known then as Lifetime Premier Platinum (LTPP) for heritage MR elites who'd have 750 lifetime nights and 2 million lifetime points earned as of August 31, 2018 (discussion started here: Lifetime Marriott Rewards elite status (Pre-Merge 2018 and earlier) - FlyerTalk Forums). This counted earned nights and points only from the MR side. Eventually, Marriott renamed Platinum Premier to Titanium by shifting Platinum elite status to earning 50 nights/year and setting Titanium at 75 nights/year.

For those of us who were or close to LTPP, it set up night and/or points runs to get to 750/2MM by August 31, 2018: The Race to 2.0MM Points is On! - FlyerTalk Forums