I remember watching a Merv Griffin Show, featuring Beverly Sills and Ethel Merman, where he celebrated the work of Cole Porter. They were discussing the opening night of ANYTHING GOES (1934) and Merv asked Merman if there was a standing ovation that night. She replied that there was, and he commented that the standing ovation was a rare event back then, not like 'today', where it's very common. That had to have been in the early 70's (I was in high school, the earth had just cooled), so this phenomenon of all shows getting a standing ovation has been going on for at least 35+ years.
Having said all that, I distinctly remember seeing GIGI in San Francisco in 1973 and it did NOT get a standing ovation, but at LORELEI, several months later, Carol Channing did get a standing ovation.
'Our whole family shouts. It comes from us livin' so close to the railroad tracks'