I'm surprised the world isn't more populated, specially NEC. You have whole yards that are empty. Even as a passenger on a real train it's always awesome to see some freight train on a siding/engines sitting around or other various activities. Fix this.
Rolling stock was removed from both CSX:HH & NEC to improve performance so I can't see more being added until DTG manage to get a dramatic performance improvement in their Simugraph and artwork. Sorry to be the bearer of bad news.
They are all busy pushing out the new DLC... or it's the usual DTG silence, who knows. Maybe that's why they removed the dev tracker, because there is nothing to track
Every single route that has been produced on TSW so far lacks rea life amounts of traffic. Mainly due to the lack of rolling stock available.
The dev tracker was switched off because it was giving problems to Dovetail Live. Changes are still being made behind the scenes and we would like to bring the tracker back. As SamYeager said, stock was removed to improve performance.