The old code blocks had syntax highlighting, the new code blocks have none. You can select many languages, but they are all pretty much the same exact thing. I have no idea why you removed a great feature, only to make the Code Block a major downgrade from what it used to be. 

Please bring back the syntax highlighting the old code blocks had. Without it, selecting the language is practically useless and serves no purpose at all. There are many open Issues about adding languages, yet what's the point when that language is going to be the same as 99% of the other languages?