I have never had one that has been repriced at the current rate. It is repriced at the exact same rate as the double booked at except the entire fare is now shown for guest 1. The price (other than the lower taxes) has always remained the same
The problem is that they fill a good portion of the double occupancy guarantees with triple and quad occupancy cabins. The ship has 80% of the cabins designated for triple / quad which is why so many doubles are forced to book guarantees.
Something nice that we saw on Odyssey in March and they said it was the first week they did it was restauarant staff in the terminal prior to boarding making reservations. It was fabulous, made all mine in yhe terminal at 10:30 prior to boarding.