I have seen various confirmations that state no shows will be billed for one night's stay. Some will take the points some will bill $'s. Every reservation has required a CC to confirm the booking. The biggest difference would be the charge will show as a swipe if you actually show up and they swipe the card vs. not if it is a no show billing.
Hotels are getting real bad with bogus "extra" charges like resort fees and the such. I'm not surprised to hear one go for the ultimate money grab in denying a point stay and insisting on cash for the stay upon arrival. That's one of the most vulnerable times while traveling. Glad to hear the OP was able to thwart this move and found other accommodations.
My bet is Choice will do no more than just return the points (and watch your account for months later so they don't disappear again). They don't seem to have any power over a property since they are all independently owned and operated. I'm sure most properties will not notice much difference in their bookings if they left the Choice program. Just like they won't miss me leaving them behind.