Nah, not even.

It makes the world cool. It embodies the RPG idea of rare/unique items, as well as offering a tremendous feeling of authenticity to a world which we only see a few years of, but has a history dating back hundreds or thousands of years. We get a reference point to our own history, in which there have been regional "dark ages" and renaissances. Valyrian steel has plenty going on without needing some yet to be revealed magical attribute.

I'm not ruling it out, but it's just not needed. As it stands, Valyrian steel in Game of Thrones is already better integrated and more useful from a narrative perspective than light sabers are in Star Wars.