As a general practice I never rely on the vendor, whether it is an air carrier, hotel or other, to notify me of anything. In this day and age, it is easy enough to monitor upcoming travel proactively.

I also would not use broad-based terms such as "Marriott" rather than a specific property. Bottom line is that Marriott's systems are dependent on what is fed by individual properties. Even more so during a pandemic when staffing may be minimal.

Bottom line is to monitor your reservation as well as more generally, your property's web page and what is written. May even be worth a call (not to a toll-free line, but the FD).