The UK rights laws are crazy. How can one person ban an episode of a franchise they don't own from getting rereleased? Much less the relative of someone who worked on the episode? Its weird enough that the BBC doesn't own the characters created for the show like The Daleks, K-9, etc, but its absolutely asinine that the son of someone can get the first episode of Doctor Who blocked. The rights to airing episodes should never be up to random asshole relatives of people that just worked on the episode.
Imagine if (just as an US example, I'm not saying that this person is the kind of person that would do this even if they could) Rod Roddenberry got annoyed one day and could just Thanos snap Star Trek out of existence. Or if Paul Dini went insane and his 26 episodes of Batman: TAS were just gone from streaming/rerelease.
I never want to hear anyone complain about the US Copyright system ever again. Sure, it takes forever for stuff to go public domain and some people don't like that, but at least random people can't remove parts of history on a whim just because they feel like being an asshole.