It feels odd to talk about how a contract ends when you’re entering a brand new relationship with a publisher. Both of you feel like this is a Great Thing, and it’s all shiny and celebratory and marvelous. And maybe your relationship will be that way.
But the law is all about planning for the worst-case scenario, not the best case. It’s all about protecting someone, so that someone, in my opinion, should be the writer, not the publisher.
Since 2009 or so, publishers have gotten quite nasty about contracts. In short, they’re refusing to let any contract terminate.
This is causing all kinds of problems for writers.