There's a lot that we still don't know about what's going to happen in Thor: Ragnarok. However, it appears that we may have a confirmation of at least one significant Thor character who will be returning for the new film. A new ad spot for Talking with Chris Hardwick includes Jamie Alexander, and it tags her name with Thor: Ragnarok, implying that Lady Sif will be back after all.
While Jamie Alexander has a solid gig these days on TV's Blindspot, she came to the attention of many thanks to her role as Lady Sif, one of Thor's warrior compatriots on Asgard. The actress appeared in both previous Thor movies, but indications had been that maybe she wouldn't appear in Thor: Ragnarok. The actress herself answered questions about the movie with apparent ignorance, and some sources had implied that her commitments to her TV show would prevent her from appearing. However, all of that came after Alexander herself had implied that not only would Lady Sif be in Thor 3, but she also said the character would have a larger role than the previous films. At this point, the script has almost certainly gone through many changes but it would appear that Alexander will appear in a role of some size. Either that or somebody at Chris Hardwick's show goofed.
Of course, the fact that Lady Sif will apparently be in Thor: Ragnarok may not be a good thing for the character. We've seen in the trailer that Asgard is going to catch fire, and we're guessing that a lot of its citizens will not survive the event. Hopefully, we're not setting ourselves up for the loss of Lady Sif.
If Lady Sif is going to be in Thor: Ragnarok then we have to wonder if the rest of Thor's warrior pals will be along for the ride. The Warriors Three, Volstagg, Hogun, and Fandral, have also appeared in the two previous Thor films. There has been evidence that Volstagg and Hodun will be there, as actors Ray Stevenson and Tadanobu Asano were both in Australia during the time Ragnarok was filming there. If the two of them are in the film then one would expect Fandral to be there as well. However, the last thing we heard, Zachary Levi was not aware of any plans for him to appear.
We're hoping this news is accurate because we want to see Lady Sif again. We'll find out for sure when Thor: Ragnarok hits theaters in November.