D will still remain, when you copy the directory, it will only replace the files in the old one, it doesn't delete the old directory first and then write the new one. If you want something to do that you'd need a script something like
dirlist=( `ls -Qd */` )
for (( i=0; i < numdirs; i++)); do
rm -rf rss
cp -r $SRC ./
although that is just a quick example, and may not actually work properly or you.