According to Doug Lynch at xda-developers.com:
Android TV owners recently received an update across multiple platforms that have started to display sponsored content with a "Promotional Channels' title in the launcher of the Android TV software. We're currently seeing reports that it has shown up in Sony smart TVs, the Mi Box 3 from Xiaomi, NVIDIA Shield TV, and others. This has been an incredibly off-putting change for a lot of Android TV users. What makes matters worse is people were unable to disable the ads at first, but Reddit user Felisens seems to have figured out how to disable them.
[...] Update: Google's response
A Google spokesperson gave us the following statement:
Android TV is committed to optimizing and personalizing the entertainment experience at home. As we explore new opportunities to engage the user community, we're running a pilot program to surface sponsored content on the Android TV home screen.
(Score: 2) by NotSanguine on Friday April 05 2019, @05:53PM
My apologies. However, I thought that the quoted section explained this fairly clearly:
I don't use Android TV and don't have any of the products mentioned. In fact, I didn't even realize that Google had any control over third-party TV devices that used Android. But it was pretty obvious to me what they were talking about from the context. As such, I didn't think it was necessary.
Just so it's clear now:
Android TV == A fork of Android used on TVs.
No, no, you're not thinking; you're just being logical. --Niels Bohr