It would be neat to see preservation societies do a sort of “fundraiser” through releasing route addons, but the time it takes to create a route and high-standard stock these days has likely increased ten-fold (or even hundred)?

More likely, it would be cool to see locomotive preservation societies have someone create their prized possessions for Trainz, then release them with all funds going towards restoring and maintaining their loco. A CoBo Class 28 and Baby Deltic Class 23 spring to mind.