Does adding the "Do Not Track" (DNT) to HTTP headers make one a target for extra tracking, such as in-depth browser fingerprinting?
I would say no.
This is from Wiki:
"There are no legal or technological requirements for its use, when it's enabled by default on browsers. As such, websites and advertisers may either honour the request, or completely ignore it in cases where it's automatically set".
So if an organisation wanted to track you and DNT was set, they could just ignore it and carry on and track you anyway. Any respectable organisation that observed DNT would probably not engage in such behaviour.