This is hardly news, Trek's performance road lineup has been nearly 100% 50-34 for years. The exceptions have been things like some of the Race Shop Limited bikes.

It's not like the other manufacturers provide much in the way of chainring choice through model selection, either. For instance, Specialized uses both 52-36 and 50-34 on various road models, but it's mostly broken up by bicycle tier; if you want a high-end Specialized, it's pretty much going to come stock with 52-36.