For people taking part in the parade, I doubt that. Extreme example is Jackie Kennedy. “I was sitting next to the president” identifies her pretty well.

There were people in the crowd who can easily be identified, too. For example, Zapruder’s testimony would have to leave out that he shot a movie and was life on television that day, and quite a few other details to anonymize it.

I’d mostly agree with that. After sufficient years have passed. Name isn’t the only way to identify someone.