The Delta info is not about temporarily reducing flight schedules. It's about downsizing the airline, and Delta is certainly not alone..
As I understand it, many of the airlines were holding on to older aircraft they intended to replace -- possibly due to the 737 Max problems. I guess their thinking is that they are going to get hit so hard, for so long, that they are going to be forced to significantly shrink their airlines for several years.
I suspect some of them will use Chapter 11 bankruptcy to reorganize as much smaller airlines with lower costs and then rebuild from there.