These two Sunday School manuals disappeared around the time there was discussion of a different curriculum coming for adult members of the Church. There has been no official announcement, this is my personal opinion, and I have no insider insight, but I believe we will use the Sunday School New Testament materials next year and then there will be a change.
Again, this is my own opinion, and if there is not a change, it would be a simple matter to make the missing two courses available again. I am sure they would if something else is not used in its place. These same two course manuals were also removed from the Church website around the same time.