AMA rules don't seem to specify. If I rider goes to Lorettas in the C class, do they have to go B immediately when they are back from Loretta's? Seems to me in the 80s and 90s once you returned from the ranch, you were now a B rider. Is it not like that any more?
I think back in 05 when I followed it you were advanced the following year. They aren't going to put a new list out half way through the season. Until they post a list, I'd say C class stays the same unless riders want to advance. And at that point, why wouldn't you?