Reddit users thevincentasteroid and MMD3_ posted about an auto-playing video ad (with sound) on the home screen. The ad is for Chicken Tender Wraps from Carl’s Jr. When it begins auto-playing, it pushes all the other UI elements out of focus and goes almost full-screen, returning to the home screen after it has played through once.
I bought the Chromecast with Google TV (older version, not the newer 4k one, which I also own now) when it first cane out.
The home screen hasn’t changed since day 1 when I plugged it in.
It always had an ad at the top, and you always have had to purposefully move the cursor onto the ad itself and not touch anything for multiple seconds before it played.
I owned the OG chromecast and chromecast 2 before that, and you are right, that one didn’t have ads, but it also didn’t have much of anything really.