The last year I was there..in southern California, the gyms came together and decided that. It was in 2006-2007 for the first year. I know that because our new level 5's competed their first meet in the beginning of June, for fun, but if they made the scores, they were going to have to compete level 6 in the fall.
Uh...way to go SoCal...
That is completely illegal according to USAG R&P. I'm sure they talked about it, but I can't see how they could have gotten away with that.
USAG has never had mandatory move up scores, and States can only make up their own rules as long as they don't confilct with USAG.