This was my thinking also, why would the cruise line move an inside all the way up when they can get a cascading effect by moving an ocean view to a balcony, an inside to an ocean view, etc. Plus, it would seem you are incentivizing people to purchase the cheapest cabin, then have them try to get a higher cabin on the cheap.
The reason for my question is that I booked an ocean view as it was the cheapest available however it is $1500 more than an inside. So if an inside becomes available before final payment, I thought about moving down, then using the $1500 difference in price between the 2 to bid up to a balcony. However, it looks like from what is said, doing that could limit my bidding options, so I may not take the risk.
By the way, thanks for all the responses, much appreciated.