Netflix and Amazon series writers are all the same union as the broadcast nets. So it's more likely the new kids would look to license (more) archive material from the older networks, as the oldsters have a much deeper inventory. If recent Netflix and Amazon original shows make their way to the broadcasters more rapidly, the value of Netflix and Amazon original content to the consumer diminishes greatly.
Probably won't affect Netflix, Amazon, or Hulu. Their contracts are not broadcast contracts like ABC, NBC, CBS, etc have. I would expect they have their own streaming contracts, and Netflix at least is known for offering better deals than Hollywood and the Broadcasters when it comes to making their original content. Joint-Developed content, however, might suffer though.
The irony is that it may prevent them from licensing material to the broadcasters though.