This has a script, Director and Lead. Tim Miller was hired to Direct because he came cheap and they needed that in order for them to do the film they want (which is a hard R) they wont have a big budget like other Super Hero flicks.
Donner on the R rating
If we make the movie it needs to be a rated R film. Otherwise you can’t make it. As for Tim, most of the advertisements for the games you play, everybody plays, he does those. He’s just…it would give it a very different look, a very different feel, which would be totally appropriate for Deadpool. Again, I don’t want people to feel like they’ve seen these movies before. Every movie has to have its own identity, and he will bring a whole different visual style to it. Very different visual style. And he’s funny! He fits right into that world. He fits right in. He’s perfect.
More things lead to it being R then not. The Script they have will need to be scrapped if they want a pg-13. But your right, there is no movement right now, doesnt mean its not gonna happen for sure. There is zero evidence of that besides the "If we make it" that gets mentioned every now and then. Its said to shoot next year. Nothing has been mentioned of that not happening.