Oh, this is great! Both DaveRam's question and Andy Smith's P&Y rumor. You guys made my night.
I think this is a great idea and a much-needed twist for the Beatles' saga. They should definitely do it. Paul will marry Yoko, vanish into the fastness of the Dakota... and then the rumors will begin to creep out. He hasn't been seen for months... no friends can reach him...
He's dead! But how will anyone prove it? All they have are Yoko's assurances that he's fine, just fine... just deep in thought, in the back bedroom, perhaps in one of the closets... *starts scary music*