I wonder if it is or will be possible to run some trains using other routes in TSW 2020 ? And also for Train Simulator 2020. Latter seems far more flexible.
If you're asking if content for TSW and TS2020 can or will be used interchangeably between the 2 platforms then no, they are 2 completely different games in every sense. If you're asking if trains can be used interchangeably on different routes, that sounds like something for the editor. There is a mod that allows you to do just this and the link is somewhere in the forums here that was posted the other day if that tickles your fancy.
You need TS2020 to run trains over routes they don't normally operate. There is a scenario to run the UK Class 66 off the GWR route over the Rhur Sieg Nord on a tank train but I don't expect the Class 47 to be used outside the UK in TSW http://www.trainsim.cz/?mod=article&showid=2280&query= Peter