I only peek at string theory occasionally to see how it is going - last I looked: "no"... though that is the short answer,
Probably string theory is best thought of as a meta-theory: a kind of scaffold on which a theory of everything may, eventually, be constructed.
Studying string theory can get you an understanding of symmetries etc that crop up in QM ... that sort of thing. Just like higher dimensional geometry can lead to understandings in 3D geometry. In a kind-of abstract way. For instance, it may be possible for someone to find insights into how QM and GR do not work together.
At best we would expect a new theory to provide insights into the old one in much the same way that the heliocentric model for the solar system provides insights into the geocentric one and Newtonian gravitation provides insights into Ptolemy's epicycles.