I'm curious about this statement that appears at the bottom (and I've see this before obviously):

"Thanks to Sam Altman, Mike Arrington, Paul Buchheit, John Collison, Patrick Collison, Garry Tan, and Harj Taggar for reading drafts of this, and Marc Andreessen, Joe Gebbia, Reid Hoffman, Shel Kaphan, Mike Moritz and Kevin Systrom for answering my questions about startup history."

(my emphasis)

To what extent do these individual contribute and/or suggest corrections of an essay like this?