Let's say that they want to slow down sites like TPB and Vodo while making Netflix faster.
Instead of "making everything normal and making TPB slow", which would be a bad for marketing and would be avoided by VPNs, they'll make "everything normal and Netflix fast", which sounds much better in marketing and you can't avoid with a VPN (if you use a VPN, everything will be the same, except for Netflix which will be slower).
This is the same thing that is happening with zero-rating in the EU: If you use a VPN, the only thing that happens is that you'll have limited traffic for all services.
The FCC was inquiring into these programs until Ajit Pai's appointment as chairman: https://www.geekwire.com/2017/fcc-ends-inquiries-t-mobiles-b...
And the EFF has criticized these programs as a violation of net neutrality: https://www.eff.org/deeplinks/2016/01/eff-confirms-t-mobiles...
Getting a significant number of users on VPN would take a long time...
A VPN solves this problem quite well. Only exception I see is overall bandwidth usage. They'll obviously still see the total amount of traffic going across their lines and may throttle that, but that would apply to everyone equally, which I don't have an issue with. Since they won't be able to see the traffic due to encryption, they can't inhibit/block certain sites or services. Nor can they inject ads or anything else into the HTML responses. They would also be essentially blind and unable to build a profile about you to sell.
Perhaps they will try and charge a VPN or encrypted data surcharge.
But what will happen is that ISPs will stop upgrading their "regular" networks, and upgrade only the "fast lanes" networks.
VPN providers will either be outright denied access to those fast lanes or they won't be able to afford using them. So in a few years, whether you're using a VPN or not, you'll still be in the "regular" (read: slow) lane, while the big companies will likely have to move to the "fast lane" (and pay the ISPs for the privilege).
The more time passes, the worse this will get for small companies, as the needs for data consumption and bandwidth increase, so eventually internet users will slowly move to the fast-lane-using services and dump the others.
Also, the more money the ISPs will make from the "fast lanes" the less incentive they'll have to upgrade their regular slow lanes (unless fierce competition appears, which may not), because it just means companies will have bigger "incentive" to pay them for the fast lane access.
Also, you can just keep track of known-business or known-personal VPN endpoints. VPNs don't hide the fact that you're using a VPN, nor which VPN you're using, from your provider. (You could still use Tor pluggable transports, but then you've completely given up on performance.)