That would be a very bad idea for Netflix. They would be breaching contract on thousands and thousands of customers and open them self to probably a very large class action lawsuit. Although I could be wrong IANAL.
While I agree this is a bad idea---the whole incident shows they have a direct link to the hearts and minds of their subscribers using these ISPs and are not afraid of using it (the biggest development in the net neutrality fight since AT&T's Ed Whitacre opened his foolish mouth and started it 8 years ago)----they could punt subscribers on these ISPs by simply not renewing subscriptions as they finish.
I'm sure they're not representing they'll be providing their service forever, and e.g. issues with content providers means they can't even promise they'll be supplying access to any particular stuff beyond what they outright buy or produce themselves.
Maybe it will, or maybe it won't. And if it will, it may come after Netflix' US business is irrevocably damaged. It's not a sane choice for Netflix to make.