As far as I know, San Diego stations were not on LA cable. I think the LA Times probably listed San Diego stations because the Times is SoCal's largest newspaper, and is probably read by a fair number of people in SD. In the 50s and 60s, the LA, SD and Santa Barbara markets were all listed in the same TV Guide. As the number of stations grew, they got separate listings.
I grew up in the Foothills near Glendale in the 50s and early 60s, and we could often get San Diego stations over the air - if atmospheric conditions were right. But when Cable TV came in (mid 60s), San Diego stations were not included among the selections...really, there wasn't room. Since cable in those days just came in over your regular VHF dial, there were only 12 channels. LA already had 7 stations (2,4,5,7,9,11, and 13), and the Cable companies filled up the other 5 slots with the LA UHF stations (28, 36, and others I can't remember.