I guess it will be up to the ISP's to purchase or update their Switches to the new firmware (if it is firmware), is would be costly and would take a lot of work and down time. I've thought lately that I would move to an ISP that had no connection with subscription TV.
The shut off would be to the main up-streamer, they are not bothered about the minions that are receiving it. had to prove who in the house was watching the content.
As you say the internet is always one step ahead of the powers that be.