Well that maybe true but school systems around the country don't go by WDW spring break rules. My little sister is on hers in Florida this week.Here in Indiana most were off last week but some school systems are off this week.So with that said it may be packed due to some school systems just starting spring break.One other thing to think about some school systems do year round schooling and get 2-3 weeks off for spring break due to this.
I think it's Spring Break/vacation at at least one school/college from the end of February through the end of April. Of course some weeks are worse than others but I think you kinda of have to expect some increase in capacity during those weeks.