It's an option that individual channels can disable. Granted, it's opt-out, but YouTube emailed creators several times about it well before:

> Effective today, you can turn off automatic dubbing for your entire channel in your Channel settings > Upload defaults > Advanced settings > Automatic dubbing.

> Once auto-dubbing is enabled for your channel, while uploading a new video, you will also have the option to turn off automatic dubbing for that video.

So if you're seeing auto dubbing on a video by a creator who clearly pays attention to YouTube's algorithm and should be aware of the feature, then they deliberately opted to leave the option on, probably thinking that it can't hurt.