Marriott has Look No Further/Best Rate Guarantee (LNF/BRG) that does something similar if you fill out a claim form - https://www.marriott.com/look/claimForm.mi

(I've never done it, but there's a thread where folks discuss when they've successfully or unsuccessfully filed a claim under this program - https://www.flyertalk.com/forum/marr...on-thread.html)

(Edit - Looks like Sharon beat me to it!)