I'm not familiar with that old tale about Zeldman. It's true that assistive technologies don't know about CSS class names but CSS absolutely can affect a non-sighted screen reader user's experience.

I don't use Tailwind so I don't know if it makes it easier or harder to do the right thing when needing to hide something from everyone or only visually hiding something. Because it's CSS, it can't take care of only hiding something from assistive technologies.