Whenever I see something like this I put it on a 24hr hold. Then do the dance with trying to get the price adjusted. Generally even when it's new bookings only they will do it. The theory always was you could just cancel and rebook (as a new booking), well that was in the days of all refundable deposits.
Now with NRD that threat comes with a cost (just like it always has with the UK). Used to be it might just cost you the $100 pp penalty and you would get the rest in FCC. Well now you lose the entire deposit so it's much less likely that people would be willing to do that.