It did! Radiolab has a fantastic podcast on how that evolved into confusion and concern:It happened on radio too. Orson Welles radio play of H.G wells war of the worlds in 1938 had a massive effect on the CBS listeners
The programme was listed as drama, in a current drama series, on Halloween, with the continuity announcer making it clear that it was a drama.It was that programme that changed the way TV was listed.
It did however have a massive impact when Ofcom came to create their broadcast code. Any "fake" news, or spoof documentary, for narrative purposes has to be presented in such a context that an audience could reasonably deduce that it's not real.The programme was listed as drama, in a current drama series, on Halloween, with the continuity announcer making it clear that it was a drama.
It didn't change the way tv was listed, because the actual listing, at the time, was accurate.