A friend shared with me a rumor that I haven't heard before, and I can't verify it anywhere. He said that a one day ("single day") pass would not qualify you to make a reservation for SW:GE. I am assuming he's referring to the sign-up system and not the hotel guarantee. Have any of y'all heard that? I haven't heard anything about a single day ticket not qualifying for reservation whether through the hotel or sign-up system.
Strangely, I'm seeing less and less from Disney about the sign-up system, and more about the hotel guarantee. I get hotel stays would be greater revenue for Disney, and it offers definite access (if you can get into DL park), but when the SW:GE reservation dates rolled out they initially described both types of reservations equally.