Yes -
That said it does not in many cases.
If a upload is done and all is 100% successful it does clean it up. However if you watch a failed upload many times the files are left behind.
So in our system we have to go in about once a few weeks and clean up a little by hand. (As we know when people can upload items it is a little easier as we just -rf under each of the cell locations).
VCloud has been getting better but it still is not good at keeping itself clean. (It still leaves items in VSphere on some failures, and leaves items in transfer space all the time)
Please make sure to let support know so they can log it as a customer bug - many times it seems that even if issues are pretty well known they are not fixed as no customer impacting issues has been opened with engineering at VMware.