https://blogs.fangraphs.com/instagraphs/why-gerrit-cole-never-came-into-game-7-of-the-world-series/
I've been harping on this for awhile, but apparently Cole and Hinch 'agreed' on 2 conditions. Cole only enters during a fresh inning and if they are leading. If you read the comments, people question who came up with these rules.
I can't imagine a Manager would be the one trying to restrict when/where he's used - unless you're concerned that he's going to try and force his way into a game or get too worked up in the pen or something. We'll probably never really know, but I think there's a decent possibility that Cole dictated when and where he was going to pitch instead of simply saying - "I'll pitch whenever and wherever you want me to coach"