Up until that time, there were no widely known or documented instances of Leonard Bernstein crying while conducting during his performances.
Leonard Bernstein was a renowned conductor, composer, and pianist known for his passionate and expressive style of conducting. He conducted many acclaimed performances with various orchestras, including the New York Philharmonic. While he was known for his emotional connection to the music and his intense interpretations, there is no public record of him crying while conducting.
However, it's worth noting that musicians and conductors can become emotionally moved by the music they perform, and it is not uncommon for them to express their feelings through body language, facial expressions, or other non-verbal cues. These emotions can be a part of the intense connection they have with the music and the audience.
If there have been any developments or new information after 2023, I would not be aware of them. To find the most current and accurate information, it's best to refer to reputable sources or conduct further research.