Are you adding a large % of overall water volume to the tank with the sump upgrade? If not, then no. But if you have a 24 gallon nano cube and go to a 40 gallon sump. Then you might have some cycling going on.
As long as you kill your return pump before you start messing with te sump you should be alright. All the crap at the bottom of your old sump will get washed out