I don't know
However if I would have said:
ln -sf /mnt/newhd /media/newhd
Then he could keep his existing files going there until they run out, then move them up one directory (but could still do that with changing the mount point too).
So not really an advantage, but rather another option
Also, the "changing of the mount point" wasn't there when I originally replied, so I didn't see it until after I submitted.
And 1 more thing:
I don't know why, but I prefer symlinks on my box over changing mount points, I use them all over the place instead of remounting a device elsewhere, really, I don't have a good reason I just do it.