What do you know: Even with “Harry Potter and the Deathly Hallows - Part 2’’ (2011) finally, satisfyingly wrapping the series, the jeopardy continues for Harry, Ron, and Hermione. After a fashion, anyway. This week’s arrival of the final chapter on DVD and Blu-ray comes with an atypical, consider-yourselves-warned announcement from distributor Warner Bros. that a moratorium is being placed on the franchise.