You will get the full YC experience which is amazing. The YC balconies are situated within the YC so there is no way that they could deny you access, your room card opens the doors into the whole YC area. Last year we bid for a YC upgrade, we were in the same position as you with our booking still showing the original experience but the room in YC, no problems once onboard.
Beware though, once you have experienced it you won't want to go back, this year we booked and paid full price for YC and it was worth every penny.