It's set during the Second Age, at least three thousand years before LOTR. So yeah, new stuff. Some character who were around then could show up like Galadriel and Elrond (BUT NOT GANDALF HE WASN'T IN THE MIDDLE EARTH THEN.)
I SUSPECT it'll be all about the first rise of Sauron (he started off pretending to be a good guy) and the fall of Numenor (Atlantis-like island.)
As Alatar and Pallando actually arrived in Middle Earth during the Second Age, long before Gandalf, that might be possible. But the show probably wouldn't be able to use their names since they were only named in books edited by Christopher Tolkien (remember how they were referenced but not named in the Hobbit movies.)
Hard to tell anything from that name reveal thing. If that's "young" (actually already thousands of years old) Galadriel's voice then she isn't really trying to sound like Cate Blanchett. But at least she says "Mordor" right.