UMM... HELLLLOOO? ZERO RESERVE REQUIREMENTS FOR BANKS???

They could, but I have no idea how long they will do it for. The shorter they do it, the better. The problem will be if banks go hog wild and loan out most of their reserves, they'll have to rely on those overnight repos to make up the balance when they reinstate a reserve ratio. Maybe that's why they are pumping trillions into the repo loans.
It's actually not terrible in the short term IMO, but they can't leave it that way and expect it to push off a recession. If it does push the recession out, it's going to be even worse when they have no more stops to pull out because they used them all now.