I'm pretty sure next and previous are older than new file and print file both of which have little use in this context. You could also see it as navigating lines of text vs navigating results in a list (ie search in less/vim) if you want to be pedantic. In (Neo)Vim <C-j> in insert mode inserts a new line below the current and <C-k> inserts digraphs. N/P are not necessarily inconsistent.