I'm sorry, I've used for years the ECB81 in medium scale (on a Mustang), short scale (on a Gibson SG, Danelectro Longhorn and Ibanez Mikro) and long scale on different Fender basses.
never ever experienced this difference in construction.
same with every short, medium and long scale set of D'Addario EXL and Prosteel, and Ernie Ball.
the only set that may differ is the Rotosound RS77 set in long and short/medium scale, because it changes in the outer wrapping, which on short scales is flatter and smoother.
They're generally correct, a shorter scale means thicker strings.