If nothing's being done to rectify the lack of timeliness of downgrades from MARSHA to properies' PMS that could translate into (in an oversold situation), that despite some inventory being freed-up, that someone will be walked unneccesarily.

I've certainly been processed a goodly number of "do-overs" and cancellations via marriott.com, but I guess I can count my lucky stars that I've never experienced the problem.