I find this theory compelling, especially because of the conspicuous absence of anything to do with Obi Wan in this movie. Yoda was also absent, though, which could hint at a more general wiping of the slate relative to old Jedi (keeping the theme of most people forgetting about them.)

I have my own pet theory, which I write about below. I believe that Episode 7 is setting up Rey to be the villain:

http://polymathpolitics.blogspot.com/2016/01/star-wars-episode-7-best-movie-of.html?showComment=1451867697394#c5390073418354577377