"Has anyone heard of this kind of thing?"
Yes. I have heard of it. It's called additional dealer profit.
Teflon does not bond to polymers (Which is what your paint is).
Could it?
I suppose so. Teflon bonds to aluminum pots doesn't it? I wonder what temperature is used to bond the Teflon to the pans.? I wonder what that temp would do to the rest of the car?
THere are NO protective coatings that do not wear off within a few months. Even Zaino and some others that ARE polymers that bond to your polymers, won't last a year.
As for rustproofing, the Murano and all cars built in the last couple of decades come with rust proofing. THey even come with a factory warranty against rust now. Read your warranty and you will see it in there somewhere.
At this point, some people say something like "It's your money, and it can't hurt anything, so go ahead and get it."

Not me.
I have seen far too many factory paint jobs damaged by dealers.
They may not consider a swirl cut in the clear coat to be damage, but I do.
I wouldn't let any dealer put any "miracle" coating on my car.
Homer