I have read about as much on the FE theory as I could find by googling and haven't seen anything regarding their views on other planets....
Mostly what I have found from the info I have read is conspiracy, conspiracy, conspiracy, evil scientists, liars, etc.
Maybe I haven't read enough info yet, but from what I have read, I have yet to see FE's views regarding other planets.
However, judging by what I have read, they would probably claim that we have been lied to about the other planets existing as well and need to be set straight.
Well, FE's, good luck setting us straight