It's a very small thing, it doesn't change much.

The Greek emblematic quarter in classical age is the "Amphitheatron", and it is represented with a nice semi-circular structure. 

But the word amphitheatre refers to circular (well eliptical actually) buildings, litterally meaning "all around-theater" or "double theater" 

The most famous example of amphiteatre is the Coliseum in Rome, since this kind of structures were typically roman. 

Again it's a small thing, and for me they could name the district "yankee stadium" and the game will still be great, but I wish this will be noticed and changed.

PS: in case this post wasn't enough pointless; the design of the in game theater looks more roman and than greek, but even I don't care much about it