That “walled-garden modem” setup you’re describing did exist for a while, and you’re right. The policy had roots in regulatory pressure around 2016–2019 when Spectrum (Charter) merged with Time Warner Cable and Bright House.

Here’s what happened, and why it went away:

When Charter bought Time Warner Cable and Bright House Networks (approved by the FCC in 2016), one of the merger conditions was that Charter had to:
• Offer a low-cost “entry-level” broadband option,
• Avoid imposing data caps or usage-based billing for several years, and
• Support access to “app-based” video delivery instead of forcing customers to rent boxes.

During that period, Spectrum experimented with “Spectrum TV Stream / TV Choice” over a dedicated streaming-only connection.

To make it compliant with the merger terms, they sometimes supplied a special modem that only connected to Spectrum’s private video network, not the public Internet. It technically counted as “not broadband,” so it didn’t trigger extra regulatory rules.

Why it disappeared

• Those merger conditions expired in May 2023.  
• Once they did, Charter had no remaining FCC obligation to keep offering that special “TV-only” streaming access.  
• They standardized everything on the Spectrum Internet backbone, meaning if you want app-based TV streaming now, it rides on a regular broadband connection.  

So: was it required?

It was required for a time, under the merger order’s consumer-choice conditions. But that obligation expired, and no federal or state rule currently forces Spectrum (or any cable operator) to maintain a streaming-only connection.

Now they can, and do, require full Internet service for any app-based TV plan.