When the bees are made to go down to the bottom of the hive, the upper part of the hive (where the honey-filled supers are located) is more or less empty of bees. more or less means, most of the bees.
"...it means that the honey-filled supers can be left and those bees are more or less won't be in the supers." Yes. That's correct. :D Most of the bees won't be in the upper part of the hive near the supers.