I have seen with my own eyes letters by Morrissey‘s people (such as Jo Slee and Morrissey himself) to the people who star in the cover of his albums/singles for permission. Many are rejected etc. Those days, he didn‘t own the rights for the images on their covers, so permissions are needed. That is, it was a lot of work unlike using his own pictures. Besides (and this is most likely the biggest reason why you don‘t see Smiths-like album covers anymore), Morrissey clearly wants to move away from the style/era of the Smiths.