I really do not think he is going to give H&M new titles, though I believe that he might offer to give them to their children, now that he can legally do so. (Of course, if so, he will be hoping that they decline, as Anne and Edward did on behalf of their own children. Harry is a prince by birth and always will be unless he renounces his place in the succession, which I just cannot see him doing, even though at this point his odds of taking the throne are vanishingly slim.)
Technically, as the second son of the monarch, Harry's normal title at this point would be the Duke of York. The obstacle is that there already *is* a Duke of York, his Uncle Andrew. I suspect the plan is to give the York title to Harry when Andrew dies, and Sarah Ferguson, if she is still alive, would become Sarah, Dowager Duchess of York.
Speaking of Andrew, I have a feeling that we will be hearing soon that he has decided to relocate and give up his life lease on Royal Lodge, Windsor (which is by far the nicest secondary property on the Windsor estate grounds, and coincidentally, the house where the Queen grew up.) I think odds are VERY good that he will soon be told that the Wales' need the house. He and Charles were never close, and the Epstein connection was the final straw. Charles now considers Andrew the proverbial blot on the family escutcheon, and he will not want him underfoot next door at Windsor anymore. It will be interesting to see how that relationship shakes out going forward after the funeral.