I finally finished s2. I'm undecided on whether I preferred s1 or s2, I enjoyed both. I didn't like the cop out on Jigsaw - and some of the dialogue was written as if he actually had a messed up face, and not a couple scars.
Someone noted, that the Netflix deal prohibits the shows going elsewhere for 2 years after they wrap on Netflix. So Defenders season 2 could be in the works right now and be released in late August. And it could use any character that was in s1, or any character known to exist in the world of Defenders s1. So, all the Netflix MCU characters, including Frank.
This person also speculated that the Netflix shows will probably go to Hulu - since Disney will probably own that platform soon.