It was launched last year so it isn't a major player yet but Charter does have a cellular product.

https://mobile.spectrum.com/

Comcast / Xfinity is also a mobile provider: https://www.xfinity.com/mobile/

I hadn't realized, well there's the connection at least.

To be fair they use Verizon towers for their cellphone service

They also leverage their 'network' of wifi hotspots (which are just all the home routers they give to cable customers). Either way I imagine they route all the traffic through a gateway on their network so are likely to have just as much opportunity to collect data and/or modify traffic as the tower operator would.