That may be true, but I am here everyday, and I can tell you that there is no "off" season anymore. The High and Value seasons are only terms that the hotels use to set rates, they have nothing to do with the park attendance. The terms high and value seasons are terms that the hotel industry uses to differentiate what are typical vacation "seasons" which helps set the rates. These "seasons are more regionally based and not just a Disney thing.
As far as the hotels go, yes there are seasons, it may be busier in the summer because there are more out of town vacationers in the Orlando area. But also remember that during the "value" season, Florida residents, Seasonal Passholders, Conventions, Cast Members, etc are also now opened up into the mix of guests into the park whereas during teh summer their tickets may have een blocked. In those "value seasons" Disney hosts more convention groups than they do in teh summer months, many times those convention guests are in the parks as well. Therefore even though the hotels themselves may have a "season" Attendance in the parks is very busy and no longer defined by a particular season anymore. Sure there may be slow days here and there, but that is now few and far between.