Better for the publication to define the “standards” to which code is to be held, so that the code review can be more than someone’s opinion of the style/formatting, etc.
I think that both are important. While the actual quality is more important, I think a publication would want the code it publishes to follow certain style guidelines like most other content.
Also, considering that a good deal of languages have some defined style guide hidden somewhere in their documentation, it shouldn’t be difficult to just say “use the language’s conventions”.
1: see: Java, Go (hell, Go’s got a tool for making sure your code is formatted correctly), Python.