I'm with you Wraith and I also questioned their veracity on this topic.
I posted a reply asking to be provided with the source for this information in writing as I also find this extremely hard to believe. I can give you verbatim what they said but it would be impolite to pass along User names from another forum. See next in quotes:
"It is my understanding that Microsoft is slowly doing away with mapped drive support and is wanting everyone to begin using UNC instead. At this point mapped drives are basically still around as a nod to programs such as yours that still require drive letters instead of UNC paths. "
On the topic of the problem itself, i was finally able to track down the reason for it by going off site and reconnecting through a VPN. Connected Like that, i was given a lot more choices for where to start the search so I could see what was causing the whole problem. It is caused by the way the database software is directing the request for the path. Unless the User redirects Search to Begin at the the start of the mapped drive letter, it is by default using the already interpreted UNC path as the start.
SO: Hat's off to you ATH,
Essentially you are 100% correct! The software has the user already inside the UNC path before it even starts the search. This was WHY it always returned the found items on their UNC path instead of the path using the mapped drive letter. Fixing it just requires the User to point Search at the mapped letter before it begins.
So that is the end of MY problem.
But like you, I would like to know where this one person got their info from re: Windows dropping support for mapped drive letters. I promise to pass this along if i can get it.