One thing to add. At least in the USA well into the 1980’s some local stations did air movies (and TV show reruns) from 16mm copies in some cases. If a station wanted to show say “I Love Lucy” or “Andy Griffith” they would call Viacom (at the time) up and they would ship them a 16mm copy of every episode. They then either transferred those to videotape themselves and aired from that, or broadcast using the 16mm equipment utilized before videotape. I actually have several video recordings from the 1970’s time period of “Andy Griffith” show episodes aired in this manner. I know of at least one local station that continued to air Andy Griffith from 16mm copies (transferred to beta sp in their station) up until the time close captioning rules made them switch in the early 2000’s

It would be rare for a network broadcast to have been from 16mm in that era though.