It doesn't surprise me at all that he decided to delve into the music once again.
Nearly 30 years after walking away,he knows that recording a "pop" (popular music) album doesn't necessarily mean he's turnin his back on his beliefs. Also,he knows that it doesn't mean he "has" to get back into the hecticness of show business.
I think he's just doing it for not only himself,but for the fans that gave him so much between 1970 and 1977.
Personally,my first recollection of Cat Stevens was in my hometown at the local diner named Minnix's. They had a juke-box there and I'd ask my Mom for a quarter (or was it dime in '75?.
I saw the title,"Another Saturday Night" and played that selection by him. So,just like Sundown for GL in '74,I've known of Cat Stevens almost as long.