[crisp]

As you can see from the blog post, those tracking settings are/were disabled. As a developer I know that it's easy to leave wrong default values on checkboxes so I went to first disable them (it was enabled by default) -> enable -> disable.

The tracking pixel was added in test emails as well as in the actual emails nevertheless.

[shantara]

I'm not arguing with the premise of the blog post. In my case, the emails were send as "single-send", not a part of a campaign, so disabling the options worked. But the blog post was very helpful nonetheless, as it lead me to discover the mysteriously enabled tracking options, which I would have never got around to checking myself.