Thanks to the posters on this topic! I was in PH3 and waitlisted for PH2 or PH1 for Amazon cruise on Nautica in November. As folks suggested, I checked on availability on PH1 and it is showing available. I called travel agent and got the PH1 cabin. No idea why they had not reached out to let us know 3 cabins were now available in that category!
We were waitlisted last November for transatlantic on Sirena and did get the upgrade about a week before the trip.