Hate to break this one, but ND doesn't have to join a conference and is free to remain independent according to the NCAA's College Football Playoff Director Bill Hancock. The story was up on The Bleacher Report a few hours ago. It also mentioned that Beamer @VT is not happy that they have special considerations... (Paraphrasing). Army and BYU were also mentioned as schools that can remain independant and have access to the playoffs. That info sucks but let's hope that there's more to it behind the scenes.
I saw the story. And just because Bill Hancock (a puppet, btw) says they "don't have to" doesn't mean they won't end up doing so.
I don't "have" to work, but I'd be silly not to.
Furthermore, what's true today isn't necessarily what will be true tomorrow. There's already a growing mountain of belief that Notre Dame should be forced into a conference to be part of the playoff. Just because they don't "have to" today, won't mean in a year or two that can't change.