I wanted to go to the bathroom at Torrey Pines state park a couple weeks ago and was told by the lifeguard that the bathroom is locked. So instead I had to take a wizz on the side of the road in an undisclosed location.
In general, however, things are opening up in San Diego. Water fountains on, public restrooms available. Caveat, my experience is in North County San Diego which is more or less large pockets of suburbs mixed with urban areas. In general, much less populated compared to downtown where it might still be restricted.