no, but 99 percent of the time, yes.

every once in a great while you might run into a crank and chainrings that prefer a 5-speed chain so shifting is perfectly smooth, and a thin chain doesn't skate between rings.

the same can happen with an old 5-speed freewheel that has odd, wide spacing.

it's only happened to me twice where a kmc 5-speed chain was necessary -- once an issue with the rings, and once an issue with the freewheel spacing.