As I ended here with a very similar question, I’ll leave a note for others, should they have the same need.
I wanted to remove the direct link to the media from the main map page of the website, usually located at example.com/s/yoursite/map-browse
To do it, I had to edit a different file, namely:
Mapping/view/mapping/site/index/browse.phtml
and then remove or comment out the following line:
<a href="<?php echo $this->escapeHtml($marker->media()->url()); ?>"><?php echo $this->translate('View media'); ?></a>