No doubt his children could have enlightened him - my cousin and sister are the same ages as Simon and Adam and are great devotees. But my father who was a contemporary of CRT would have associated U2 with submarines.
Otherwise I can only agree with what has been said. Ludicrous to think that Tolkien fils would or should be remotely interested or impressed by such an approach and a reflection of the bizarre arrogance of the modern celebrity culture, but we live in a world where Kate Witless can claim to be a huge fan of Iris Murdoch, whom she portrayed, but in the same breath declare that but of course she hadn't read her books, she didn't have the time.
And of course I would much rather Christopher didn't have his time wasted with such ephemera while there are texts remaining to which he can provide his unique insight if he is so inclined.