Y Combinator leans on WaPo

WaPo publishes a lot of original content that's relevant to users here so citing that content here would be expected. Not all of that content is paywalled so I suspect those who subscribed to WaPo don't check to see if it is or not.

Often, a WaPo headline will provide the gist of the content so it's still informative and other media often summarize WaPo content so I can still find the important details if I am interested.

This has nothing at all to do with "Net Neutrality" though. WaPo has no obligation to provide "free" content, nor does any other web based service.