Yeah. I don't see anyone walking away from 21 million.
That said, I also don't think the C's necessarily want PP around still in 4 years. Yeah, it'd be sentimentally nice to see him retire in Green, but if I'm Ainge, I don't want Paul around still after Garnett and Allen are gone. If I'm Ainge, I try to extend Ray and Paul, but only through the end of KG's deal. That way, the C's have three huge deals (plus Wallace) coming off the books the same summer, opening up a ton of money to add young superstars to put at the 2/3/4 positions between Rondo and Perk.