Task, I see no problem in what you want to do. However, ....
Is this existing receptacle serving and actual kitchen or bathroom counter? If you will will likely be creating a code (and logical) violation by removing it.
Second, if not, and you do not want to upper box and more, there is a good chance the wires come from below the upper box. You may just be able to pop the staples loose and bring the cables down to your new box.