That's not completely true because when it comes to restaurants located in the resort you are staying at the Club Level Cast Members have more pull to get you an ADR at one of them, if the WDW website or a Cast Member on the Dining phone line said it was sold out.
A few Club Level Cast Members personally told me when they log onto the ADR system it can see they are doing it from a Club Level lounge. So if they tried looking for a restaurant where the guest was staying at 99% of the time it would be available. If it was still sold out then they could call the restaurant personally and get them an ADR.