Some people on this site think the Silver Chair will be the next movie.

I'm here to say it is not!
The next movie will be The Magicians Nephew.

Source: link

link

Fox (instead of Disney) decided that they will be skipping the Silver Chair and just going on to the Magicians Nephew.

I am very sad that the Pevensie will not be there.
I think another reason they are doing TMN is because many people say it is their favorite book after LWW.
Fox is hoping that TMN will have a better turn out than the Voyage of the Dawn Treader.