The weird part is all the Kenner versions had a middle landing leg. None of the toy landing gears were screen accurate though. The Micro Collection Falcon, released in 1982, retains the 1977 look.
The "in universe" explanation could be Han has added more smuggling compartments. There actually was a scene in the Marvel comic where the bad guys know where to look, but false bottoms have been installed, faking them out.
Will be interesting to see how the new Falcon prop turns out.