Interpreting explanation of "Universal web tracking opt-out"

In the config settings "Universal web tracking opt-out" is explained thus:

"If enabled, if a user has Do-Not-Track enabled in the browser, the Facebook Pixel module will not execute the tracking code on your site."

My understanding is that if enabled, and a user conversely DOES NOT have Do-Not-Track enabled in the browser, the tracking will be executed, however it doesn't seem to work that way.

The code appears to pass the boolean value of this setting directly to the browser:

'donottrack' => $config->get('privacy.donottrack')

I realise navigator.doNotTrack is deprecated (returns NULL or unspecified in some browsers), but I can't see where this browser setting is made use of to override the value of $config->get('privacy.donottrack'), and pass donottrack: false to the browser.

Am I misunderstanding the UI?