Exactly so. Movies could do this because there was zero financial connection with broadcast TV.
Also, Network was considered ridiculous parody. The darkest of dark comedy. Nobody thought it was talking about real issues. TV news was not entertainment when the film was made, and wouldn't be for another decade (Reagan).
Also also: an extramarital affair in 1976 was just a thing bored men did; to be expected. Ever watch Mad Men? The culture was just Like That.