I sailed this past week on the Grand Princess, and have recevied the email for the so called 'onboard "AU/NZ regional spending credit" of AU $25' for standard fares due to the nickel and diming changes which was supposed to be issued on the first day of sailing. Nothing came through, went to customer service on the second day (waited around 45 minutes to get served, being the third in line) and they knew nothing about this, and tried to argue that the credit was only for Plus packages (it was clearly not). Said they would send an email to head office. I have since disembarked and never heard from them again.
My advice: Don't expect to get this credit, despite the email, or ask them about it as soon as you board and hope for the best. It was not worth my time to line up another 45+ minutes to get a non-answer. I am aware that the customer service staff onboard are likely powerless to do anything about this.
Tangentially, they really should put more front desk staff on during sea days. Even the dedicated 'Suite and elite' line was well past the shop entrance on the second sea day. Saw more than a few exasperated passengers dealing with the front desk (more than one audibly exclaimed how disappointed they were 😛 ), and understandably (we are only human) this negatively affected the customer service staff and some interactions with the front desks were curt and borderline confrontational. Typos on disembarkation information and timing of disembarkation forms added to confusion of customers (for a 5 night cruise, we were asked for disembarkation preferences on the first day after embarkation, with the wrong location for disembarkation printed, and they required the forms to be handed in to the front desk in person, with nary a drop box and couldnt be given to your steward) all of which culminated in quite a frustration experience dealing with the customer 'service' team.
I don't blame the humans who work there, I do blame the poor management.