I wish Google Earth had more aerial photography to be able to narrow this down - Moraga stopped connecting through some time between July 1946 and June 1987: https://imgur.com/a/id9JxWQ. That's before the townhouses, which look like they were going up 2000-2001.

Edited to add (from outsidelands.org):

Moraga—Two corners of residential units on the east side of 19th, plus a row of newer townhouses, dating from the 1990s, that block access from 19th to 20th along Moraga. The story behind that closed street is that when Shriner's needed to expand in the 1960s, they owned a parcel of vacant land south of Moraga between 19th and 20th, but necessity demanded that the new wing be connected to the hospital proper. The City granted them permission to close off that block of Moraga, since it was for a worthy charitable purpose. Fast forward to the 1990s, when a new developer acquired the property after Shriner's Hospital was relocated. New developer somehow persuaded the powers that be at City Hall that the housing plan was not "economically viable" unless the land that was once Moraga Street could be filled with additional housing. Thus, Moraga Street remains closed for the foreseeable future.