I agree that the discussion is largely academic, however, with the change to Succession to the Crown, it is conceivable that either Prince George of Cambridge's eldest child is a girl, or if he has no children for whatever reason, then Princess Charlotte succeeds. Both these could marry any one of a number of male peers or dynasts of those families. Also, there is also the possibility of a change to the laws of succession to peerage, should a government choose to go down that road (as regular posters know, there are many potential problems).
If HM Queen Elizabeth, the Queen Mother had been a Suo Jure Peeress (English Barony by Writ), I do not think the title would have merged with the Crown and Viscount Linley would have petitioned for the title and surely it would have been granted. But this question is getting very academic!
Another example is James II of England & VII of Scotland. Before accession to the Throne he was created Duke of York (E) and Duke of Albany (S), I believe with the standard heirs male remainder. When deposed, James II did not legally revert to being a Duke. His surviving son, James Francis Edward Stuart (the Old Pretender), born just a few months before James II was deposed did not succeed to the Throne on his father's death (due to Act of Parliament), but didn't succeed to his father's previous peerages either - they were merged in the Crown.
There is even modern precedent on these lines - Edward VIII abdicated in 1936, and his Princely style had to be re-created by Letters Patent by George VI. Legal scholarship at the time broadly viewed that his abdication removed him from the Throne and no other dignities were returned as if he had never been King - his brother had to give them back.