It would also be weird to me for them to not have linux ports of their engines after blogging about the performance and bug squashing benefits of doing so for previous game engines.
In any event, around this time they found a lot of optimizations porting to linux that they then back ported to the windows client. This was 10 years ago, so the zeitgeist in the company may have changed, but I've certainly taken to heart the idea that you should be cross compiling to at least one different target whenever you can to improve your engineering. The earlier you start the cheaper the cost of doing so as well. (This isn't the only company doing so at the time talking about gains of cross compilation either, and not just games)
