I voted no.
I don't think this is needed since if you were to try and add them again you are brough to... This person is already in your friend list.
If it somehow helps siteload by not having to bring people up to that page [ I don't know if it does ] then I could see it being useful but other than that I don't think this an important addition.
If there was an option of being in between I would have chose that.