Ok so the Transpennie mainline is the same as the northern transpennie but with its real life form if it was added the trains would have are the class 68 and its cab car i couldnt find a photo of its cab car but it would have mark 5 A coachs the next is the class 397 so we moveing on to northern northern also runs on the line making stopping services the trains that could come are the class 150 and the class 158 thxs for looking at my suggestion *note that its the same route as northern transpennie but with the station it looks like right now*
There's a simple fix for your suggestion is turning it into modern day NTP pack which requires a rework of Leeds City because in 1989 East Coast Mainline electrification reached Leeds via Doncaster and Wakefield.
I doubt it's ever going to happen. They would basically need to remake the scenery and the line for this. After all the towns will have - no doubt - changed since the 80's. And Stations will have as well.
I think DTG will concentrate on doing different routes rather than different versions of the same route. Maybe in 10 years time this could happen but there are so many other routes that could happen instead for now.