Somehow I don't think Disney would allow for Miss Piggy to go into rehab (I wonder if Lindsey Lohan think the Muppets are still like their 2002-2005 selves, when they seemed to rely on the Simpsons/Family Guy-type humor). Still, I dont think Lindsey Lohan would have say in the idea (does she still even have the star power that Jason Segel has, which helped get the Muppets back in theaters in the first place?).
It's interesting the article says Lindsey Lohan wants a featured part in the next movie to help bring her back to the spotlight. If that actually happened, it'd be ironic, the Muppets got back in theaters due to a celebrity (Jason Segel), and then the Muppets make a has-been a big star again.