[nn3]

Usually it happens anyways, just delayed. Old people usually don't want to move, but the younger people are more flexible and move away as soon as they can if they don't see any future.

Then these towns get older and older until eventually they won't be viable anymore (or find something else to still attract young people).

So the trends are happening, they are just delayed by a couple of decades. As the average life expectation grows the cycles get longer however.