Ugh. SPG has extended its status challenge program, which allows anyone to get SPG platinum status and thereby Marriott platinum status through February 2020, if they stay 18 nights.
For Marriott elites, this is insane not least because SPG only requires 50 nights for platinum status whereas Marriott requires 75 nights. But lowering the threshold to 18 nights is ridiculous.
https://www.spgpromos.com/statuschallenge/