They have cable for their primary viewing, which means that, sure, Google isn't seeing it directly, but their cable provider has all the details of what they are watching then. Honestly, I'd trust Google with that information over Xfinity or whoever they have for cable. Verizon?
I realize that is a concern for some, that is not a concern for me.
I have accepted that most of what I do is recorded and tracked. As such, I have a few options... opt in, opt out, or a hybrid approach. Google provides enough value to justify the cost (IMO). For this reason, most of my products are from Google. I'd rather consolidate my data with a single company rather than spread it out across many.
I realize that is a concern for some, that is not a concern for me.