It's going to be interesting. I won't be hiking until mid September so I hope the trailheads will be open by then, if they have to close them for a while. A lot can happen between now and summer hiking season.
After all, it's only been 3 weeks since all hell broke loose with the shutdowns, and cases/deaths are expected to peak in the next month or so. After that, then they can slowly relax some of the restrictions. I would think that hiking, even though it's not "essential", is a low risk outdoor activity and will be allowed, even in the Sierra. Much lower risk than going to the grocery store or especially having to ride a bus or subway.
