Who is he?
Atari sells Locomotion not CS, he has his own publishing company since a few years, 31X Ltd., so why would he sell Transport Tycoon under the name locomotion and via Atari.
Let's know a bit of History2004
First at all the name of this game has been called at first time on 2004 "Locomotion", Transport Tycoon is another story , the publisher and distribution company "ATARI" buy Chris Sawyer's copyrights to distribute and sell his game.
Chris Sawyer is a independient author, however he is just a programmer and designer, He need the help of a publisher company to distribute the game.2014
Chris Sawyer and 31X Ltd. Release a game called "Transport Tycoon" for mobile devices , the game already use "Locomotion" platform, however the data files for trains and stuff are coded different. You can see diferences between TGV1.dat and TGV1.dat Transport Tycoon Mobile2015
Atari release "Locomotion" on Steam
The game has been released on Steam platform, this gaming platform started with Half Life and games developed by Valve corporation, Grow up adding Companies like "Ubisoft - Microsoft - Eidos - Atari" and today is the biggest platform for gamers, they are including old games.