You know what, I always felt these new fictional tracks were kind of substitutes for some of the classic ones using resembling aspects.
For example, as you said, Dragon Trail could be the new Trial Mountain (both have tunnels and are located near rocky mountains).
Lago Maggiore could be the new Grand Valley (both are long and technical tracks and are divided into other layouts to create shorter variants).
Tokyo Expressway could be the new Special Stage routes (both are located on a city expressway).
Kyoto Driving Park could be the new Apricot Hill (combination of fast esses and a similar hairpin).
and so it goes...
Of course, I hope I'm 100% wrong, but I always felt like that, at least for GT Sport.