Broadcast classes never went away. There are thousands of radio and television stations in the United States today that are still owned by local school districts and other quangos, and still broadcast classes and class material.
The COVID pandemic has expanded the use of broadcast classes in a number of cities, including San Diego and Las Vegas.
Hum... Brazil is borrowing the tried and tested ideas of education over radio and TV for remote instruction in rural areas.
At the same time, everybody is trying as hard as they can to stop needing them. That's because those techs suck. It is much easier to learn when you have any bit of interactivity, the more interactivity, the easier it is. Broadcast and postage are just not suitable.
The COVID pandemic has expanded the use of broadcast classes in a number of cities, including San Diego and Las Vegas.