After the Hollywood Production Code was introduced in 1934, there were drastic changes, and overt displays of sexuality virtually vanished until the late 1960s.

Source: https://chicago.suntimes.com/movies-and-tv/2023/2/2/23579862/body-parts-review-documentary-sex-movies-jane-fonda-rosanna-arquette

Thanks to the gradual weakening of the Hays Code (which was abandoned entirely by 1968) as well as Hitchcock's sheer popularity by this point, the director was able to remove that final scene despite the Production Code Administration's wishes.

Source: https://www.slashfilm.com/1461688/how-hays-code-almost-ruined-ending-alfred-hitchcocks-vertigo/