Here's something from DTG_Martin that I just saw on the Steam forums.
I don't think it has been posted here before.
Emphasis mine.
We would certainly like to bring them back Felix.AVMP however the situation is currently beyond our control. It all gets a little complicated but basically there were changes in copyright within BNSF itself. For reasons unknown BNSF no longer has the rights to the BNSF brand outside of the USA which means that our licence with them is now only valid within the USA too. We are looking into the situation however and trying to reach a deal with the new international licence holder. To be honest BNSF are playing this very close to their chest and we may never find out the true reasons behind what has happened.
http://steamcommunity.com/app/24010/dis ... 8978797646