I don't get it, Most Disney Channel shows are cancelled around this mark
Until That So Raven, it was 65 and done, and besides Raven, Suite life, Wizards of Waverly Place, Hannah Montana, and Phineas and Ferb (animated in 15 minute segments though) it's pretty much always been this way. Some have Finales, which are usually just a redone episode or the show's last season is rearranged as to air the show in that season that half way looks like it could be something like an ending, with other episodes airing later or maybe not at all, and some just end
From my experience, most DC shows, don't have proper finales. There is the movie after the fact, but some don't even get that.