if this deal is true (please post the link), it has to be for rip.
it makes no sense for pistons to give up an expiring deal in prince or jo and nate who are under contract for next year.
however, it does make sense for them to give up rip with 2 more years after this one, for jo and nate because it gets them off the books one year sooner. and there is a chance if jo gets traded there, he retires, which (correct me if im wrong), he essentially becomes an expiring contract at the end of this year.