I am not the AMA for this. I'm in marketing. Based on that and from working with some companies to who create ground-level network hardware, I can tell you:

The big providers were already working on actual, physical implementations for throttling at a packet level in 2014 and 2015. More accurately, the manufacturers who provide hardware to companies like Comcast and Time Warner were actively designing industrial-strength switches and other network components (with specific software installed) that could detect the type of data coming across from aggregate networks and throttle things they didn't want to transfer, like Netflix.

This is a very layman's explanation, but think of it like this; In order for data to get from a data center in California, to a home in Tennessee, it has to pass through networks owned by multiple telecom providers. Without Net Neutrality, Comcast has absolutely no obligation to let this data pass. And/or at the very least, this is where the actual throttling takes place, in many cases. This is how they can ensure that the internet is pay-to-play for anyone with a website or data service. They lock out the data they don't want to handle and they do so arbitrarily, without any need or requirement to notify the affected party.

Remember when Netflix accused Comcast of throttling data, but didn't really have proof (aside from showing off some graphs to the the internet). That's how the telecom providers will get everyone at first. They won't just suddenly 'tier' off the internet into packages. But they absolutely WILL sneakily throttle things that offer competition to their own services.

Maybe some of the above is common knowledge, but I'm not sure so I wanted to share. I'm not going to pretend to fully understand how throttling works at a network level, but my real point of all this is that you should absolutely keep in mind that the big providers do, with absolute certainty, have plans for taking advantage of net neutrality being destroyed.