The shuffle all is still there for Genres. I am playing it on my iPad 3rd Gen. Here are the instructions I gave to someone else. I had the issue of not being able to "Play All" in Genres.
After you select Genre and then the genre you want, look at the top where it says Repeat, Create and Shuffle.
Turn Repeat off. Then choose a song, go into Now Playing and turn off Repeat again (repeat off, repeat artist, repeat song) . Then go back to Genres, then re-choose the Genre. Now you can play all and Shuffle all.
That's how I was able to get mine to work. I don't understand why there are so may steps to do one simple function of play all. Perhaps in the update this will get fixed.
Hope this helps.