Yes. The RV Owner has the discretion to cancel your rental RV at the last minute. He can cancel it for any reason or for that matter no reason.
A RV Renter can argue that this is an unfair policy, however there could be situations e.g. if the RV is not safe for a road trip.
Such cancellations adversely affect the RV Owner’s rating therefore they will cancel only in extreme cases.
http://www.RVShare.com is working to get you a statistic on the RV Owner’s cancellation metrics.