You're right. Only access to ISP-provided 'homepage' websites, the sort bundled along with email and internet access, could be cancelled by the ISP/web host. The ISP is now entitled to block services. The company to watch is Verizon. They don't offer web hosting to new customers, but they still have existing customers using their domain hosting service. I wonder if they'll give those customers the boot. I don't know if non-ISP web hosts have any restrictions against 'unreasonable discrimination'. That was one of the main protections in the Open Internet (Net Neutrality) Order.

More related info, commentary below...
Section from the revised Open Internet Order - Mar 12, 2015

1. In December 2010, the Commission adopted the Open Internet Order,74 a codification of the policy principles contained in the Internet Policy Statement. The Open Internet Order was based on broadly accepted Internet norms and the Commission’s long regulatory experience in preserving open and dynamic communications networks.75 The Order adoptedthree fundamental rules governing Internet service providers: (1) noblocking; (2) no unreasonable discrimination; and (3) transparency.76 The noblocking rule and no-unreasonable discrimination rules prevented broadband service providers from deliberately interfering with consumers’ access to lawful content, applications, and services, while the transparency rule promoted informed consumer choice by requiring disclosure by service providers of critical information relating to network management practices, performance, and terms of service.77
   https://docs.fcc.gov/public/attachments/FCC-15-24A1.pdf

FCC Approves Net Neutrality Rules For 'Open Internet' - February 26, 2015
Welcoming Thursday's news, the ACLU's legislative counsel Gabe Rottman says:
"This is a victory for free speech, plain and simple. Americans use the Internet not just to work and play, but to discuss politics and learn about the world around them. The FCC has a critical role to play in protecting citizens' ability to see what they want and say what they want online, without interference. Title II provides the firmest possible foundation for such protections. We are still sifting through the full details of the new rules, but the main point is that the Internet, the primary place where Americans exercise their right to free expression, remains open to all voices and points of view."
https://www.npr.org/sections/thetwo-way/2015/02/26/389259382/net-neutrality-up-for-vote-today-by-fcc-board

These are the FCC's full rules for protecting net neutrality - Mar 12, 2015
The order focuses on three specific rules for internet service: no blocking, no throttling, and no paid prioritization. "A person engaged in the provision of broadband internet access service, insofar as such person is so engaged, shall not impair or degrade lawful internet traffic on the basis of internet content, application, or service, or use of a non-harmful device, subject to reasonable network management," the order states, while outlining its rules against throttling. For paid prioritization, the order explains the practice as:
"Paid prioritization" refers to the management of a broadband provider’s network to directly or indirectly favor some traffic over other traffic, including through use of techniques such as traffic shaping, prioritization, resource reservation, or other forms of preferential traffic management, either (a) in exchange for consideration (monetary or otherwise) from a third party, or (b) to benefit an affiliated entity
https://www.theverge.com/2015/3/12/8116237/net-neutrality-rules-open-internet-order-released

The FCC has reversed a 2015 rule that could change how you access and pay for internet service - 14 Dec 2017
Rosenworcel said ISPs will get the power to block websites, throttle content and encourage pay-for-play arrangements with partners while limiting others to "a slow and bumpy road." "Know this: They have the technical ability and business incentive to discriminate and manipulate your internet traffic, and now this agency gives them the legal green light to go ahead and do so.
https://www.cnbc.com/2017/12/14/fcc-reverses-open-internet-order-governing-net-neutrality.html