To my knowledge, there are no use years currently sold out at BCV.
DVC does not sell one use year before going on to the next. When sales began last Feb, they did begin with the Feb use year (or your current use year for any add-ons)- even though the resort did not open until July.
As of 2 weeks ago, they were suggesting BCV sales would continue at least until this spring.
That's a good question. With all the excitement of purchasing, I didn't ask for another use year. He kind of told me that was the use year they were "currently offering". But since I really didn't care what use year I got (partly because I didn't know that much about them) I didn't ask for anything specific. If you wanted something specific, I guess your best bet would be to just ask. Can't hurt.
We just bought a BCV add-on a few days ago, and our guide told me that BCV still has all use-years available. However, this is not true at VWL or HH (HH has only 2 use years left, I think he said).
With Magical Beginnings, they usually go by the month with the 100% banking deadline. August's 100% deadline is Jan 31, so they will probably move on to September on Feb 1. They would probably allow you to pick a month after that, but not before.