Not that I know how the mind of a great author works, but it seems that it would be difficult to write a great story without having some solid idea of what the final product should look like before you start. Like creating a product, maybe they pivot a lot after realizing that something doesn't work well (Margaret Atwood apparently did that for a book once, completely started from scratch after realizing that she had chosen the wrong point of view for the protagonist). BUT it's difficult for me to imagine they don't actually have a good solid idea of the story they want to tell before they start writing. If not book by book, then at least chapter by chapter. But hey, I'm not an author, maybe their minds really do work differently. It's possible.

I guess my overall point is that I don't think having a solid idea about what the final product should look like is the reason why authors have the "never edit while drafting" because I think they also pre-structure their ideas, and diverge on "editing while drafting" for some other reason. But of course I have no data or evidence to back this idea up.