You've got 2 echoes going on, you're sending the count of matching folders to @new but the echo of the individual matches are going to the status window. If you want both to go to @new, then you need to send both echoes there. If you only want the matches going there, then do something like

//noop $finddir(%fdpath,*,0,1,echo @NEW New Directory(s) Detected : $1-)

Note that the depth of 0 you used behaves like depth of 1, so you're not seeing subdirs unless you either change depth to something big like 99 or just drop that 4th parm. Also note that if you're trying to copy/move folders or filenames someone creates having doublespaces would require special handling, such as addressing them using $shortfn.