A:Answer Technically NO, but you loose a lot of camera functions without a subscription.
Without a subscription, your camera will record but it will record to a base station if you have one, your recordings will not go to your app feeds, so you cannot see your recordings from the app. I still have a pro 2 and those recordings show up on my app feed still ( no subscription), the pro 5s will not.
Do some diligent research, before you buy.