Personally, I'd like to see more of the traditional folk and bluegrass tracks if they're going to do country. Modern country is well-represented. It's been ages since there has been a significant upgrade in folk and bluegrass RTs and styles. Much of the bluegrass that's there is traditional and comes from the first group of RTs that were created. 3/4 and 6/8 time is under-represented in the genre, particularly with soloists.

I find jazz styles to be the most over-represented.

A style that is woefully under-represented is 80s pop and New Wave styles. Artists like Prince, Duran Duran, Talking Heads, The Romantics, etc.

And finally, many of you are correct that modern styles aren't well-represented either. The K-Pop, Hip-Hop, and even the modern pop genres that are represented aren't done very well. They feel more like an old guy like me who doesn't know the genres really well listened to a few recordings and said, "We can do that" and threw some stuff together. :-)