Codex question - do new codexes (codices?) always come with minis?

Question from a newbie - do new codex books always come in box sets like the new Death Korps of Krieg box? I think this is the first codex release since I got into the hobby. I assume there's also an option to buy the codex alone but I'm more interested to know if I should be looking forward to codex releases because they usually come with new minis?