Hi goducks!! , I've pass this on to our team to see if they can provide any insight around this.
Also, welcome to Marriott Rewards Insiders! I'm really glad to have you join the community and to see you jumping in with a great question. I, along with carat and deannad make up the moderation team for this forum and are here to help answer questions. So feel free to reach out at any time.
Do you live in Oregon? I'm in Portland and went to school at the University of Oregon. So i'm a duck fan too!
IVe heard people mention on this board and Flyertalk that as a result of their Platinum membership the hotel waived parking fees though it's never happened at any of the places I've stayed at. The nearest to that experience is the Birmingham, UK Marriott which halves its parking fee to Plats.
SInce a lot of hotels don't own their parking lots, it's really unlikely those hotels will do anything and for those that do own their lots, many don't charge, however most downtown central hotels in gateway cities do. No doubt some see it as additional revenue.
To return to your question. No, free parking is not an elite benefit, but a few (very few) hotels may offer it as such...