I don’t know about racist. But the cult of “only people who wake up early get anything done” is sure BS. Everybody has their own natural rhythm, and all can be productive within it. Just look at when your IT guys do updates. Late at night, cause that’s the best time for it. But morning people aren’t good at 2AM installs. You need late night people for that.
But the reason those installs/updates happen at night is because it minimizes the impact to ongoing functionality during the day. I’ve been part of night time releases and nobody really liked being a part of it.