It would be cool when you wake up in the morning to have a change log that tells you what the guys from the other side of the world where messing with in your project
In general it would help collaborating projects when specific actions (script changed, entity added, asset uploaded etc) are highlighted and saved somewhere.
Thats kind of what the devlog is for on private projects. It does require you to track what has changed yourself. But it works as a commit log if you want it to.