I've had the opportunity to work on two short productions for ESPN in the last two years. My role is writing the code for the screen overlays and real time scoring system.
I have very little knowledge in cameras but did have to review all the production guidelines.
Netflix doesn't mention image sensor size (CCD) but ESPN requires 2/3" or more. I'm guessing every camera they list as approved would meet that spec even though they don't specify it.
At the time I was surprised to learn that ESPN wants you to deliver all content in 720p. Wikipedia says that their Digital Center is equipped for 2160p, but they still broadcast in 720p. The archivist in me would want to receive the material greater than 720p even knowing it is to be broadcast in 720p, but I can understand the additional complexity that such a small thing can add, especially when dealing with hundreds of production companies.
I speculate that Netflix wants you to turn in higher quality video because they are factoring in that over time encoding and streaming algorithms and increased bandwidth will allow them to push higher quality feeds to end users, and they want the highest possible raw capture so they can improve the stream as technology improves, whereas ABC is content with airing footage in the future that looks as it did when it aired originally.