via the Future Forecast podcast:

Nowstalgia: hyperfast way of looking at nostalgia of things that didn’t happen decades ago but years or even months.

The nostalgia cycle is spinning so fast that the look back period is shortening to hypermodern history.

Or; the half life of attention (but not attention spans) is so short that the idea generation period has to compress to a point where sequels and building off the previous effort is the only viable option. It is impossible to both stay relevant and create from a blank slate each time.