I don't have access to edit the source file, but I can comment on it. From what I can tell though, even pinned comments aren't deep-links.
Thank you for reaching out. From what I understand from your post, you are trying to share a link for a specific comment on your prototype link to your stakeholders. If that is so, then the functionality is not available in XD. However you can share the link of the artboard on which you commented if that can help.
Please let me know if I misunderstood your question.
It's not so much the comment that I'm interested in sharing, I was just thinking about using that as a method of sharing a link that scrolls to a specific part of the artboard (e.g. the footer of a webpage), which is the goal.
You can't link to elements on page, only to specific artboards.
I get you want to achieve that effect where you can link to an anchor on a web page by adding #section to the link, and it scrolls to that, but that's not possible currently in prototypes.