I think that's the best cash-out option with such a high MR balance. That's $23,750 minus the $550 CS Amex annual fee. Yes, some hassle in opening the CS account, getting the card, using the points and getting the money out of the Schwab account, but when it's all done the OP's parents have $23,200. Plus, if they put $5,000 on the card in first three months, they'll get the 60,000 MR bonus, which they can cash out for $750 (covers the AF and leaves and extra $200).

The alternative is mileage/points brokers and risking a forfeiture of all 1.9 million MR points. I doubt any of them are offering so much more than 1.25 ccp to make that worth the risk. There's also a risk that a broker doesn't live up to their end of the deal, and then what are you going to do?