That’s not a standard Marriott practice- I’m titanium (75+ nights per year) with Marriott and have never been told when I arrive before check in time that I cannot park, nor been told that if I have to stay after checkout for whatever reason that I have to move my car. Due to flight times, this situation is quite common for me (I may land in a city on check in day at 900 am and head directly to the hotel or have a red eye out and stay at the hotel all day before flying out)
now it wouldn’t surprise me if some marriotts had a rule like this (for example the ones around
Disneyland could enforce this due to the limited size of their lots and high demand for parking) but I’ve never experienced this even at the marriotts around Disneyland (my brother lives in San Diego and often we’ll leave at 600 am from San Diego and drive straight in, stay one night at the Fairfield Anaheim resort/ Spring Hill suites, park before check in, stay one night and then leave our car at the hotel until 1000 pm the next day when we drive back to San Diego)
I will be following this thread to see people’s recent experiences because this would negatively affect our future plans at Disneyland