Dahlias 2021

I don't think they will - a tuber sprouts from the very base of the stem/just at the top of the tuber. Where you can often see the small bumps that indicate where it will sprout.
The ones with a think neck and a bulb on the end don't have sprouting points....so if you cut the stem too low ( lower than its seed leaves) it's unlikely that it will resprout. If you haven't cut the stem all away it should resprout?

After seeing that one dead top had a small tuber, I just left the rest alone so I will see what happens.