As a data point, I talked to my rep yesterday via Zoom to finalize pricing. I pushed back that I needed the Aug/Sept UY, not sure if this is new or not, but I was told currently they aren't selling Aug and Sept due to it being past the banking window for those months. Next available was Oct - April. I really wanted that Aug/Sept time frame. (we vacation anytime Sept, Oct-beginning Nov, and early Feb) I've heard of people having success getting a manager but even the manager said they can't offer it.
Initially they both said currently February was the one they are pushing for Riviera but based on our vacation patterns they said we could have March. We plan far in advance so I don't think it will be an issue.