I don't think Rand is trying to erase other Pride marches. The marches in Chicago in Los Angeles were also in commemoration of Stonewall. And I don't know about Los Angeles, but the New York City Pride March in 1970 was not "approved." It was an illegal march, though conducted with the tacit understanding that the New York City Police Department would not take violent action against it. They mostly didn't, though some stragglers reported violent interactions with cops on the fringes of the march.